Acceleration CalculatorSolve a = (v - v0) / t for acceleration, initial velocity, final velocity, or time with constant-acceleration displacement.Acceleration due to Gravity CalculatorCompute surface gravity g = G·M/r² for any planet, moon, or custom body using Newton's law of gravitation.Activity Coefficient CalculatorCalculate the activity coefficient of an ion in solution using the Debye-Huckel limiting law and extended equation.AI Water Footprint CalculatorEstimate the water consumed by AI queries, ChatGPT conversations, and large language model inference based on data center cooling water usage per query.Angular Size CalculatorCalculate the angular size of an object from its physical diameter and distance - essential for telescope selection, photography, and astronomy planning.API Gravity CalculatorConvert between API gravity and specific gravity for crude oil and petroleum products with classification.Aquarium Volume CalculatorCalculate water volume and weight for rectangular, bow-front, or cylinder fish tanksArchimedes' Principle CalculatorApply Archimedes' principle: buoyant force, floats or sinks, submerged fraction, and apparent weight in fluid.Arrhenius Equation CalculatorCalculate a reaction rate constant from the pre-exponential factor, activation energy, and temperature using the Arrhenius equationAvogadro's Number CalculatorCalculate the number of atoms, molecules, or formula units in any amount of substance using Avogadro's number.Azimuth CalculatorCompute the initial compass bearing (azimuth) and great-circle distance from one lat/long point to another.Bacterial Generation Time CalculatorCalculate bacterial generation time, growth rate, and total generations from initial and final colony counts and culture durationBattery Life CalculatorEstimate how long a battery will last from its capacity in mAh and the device's power draw or current consumption. Free, instant.Beer–Lambert Law CalculatorSolve absorbance, molar absorptivity, concentration, or path length from the Beer–Lambert lawBlackbody Wien's Law CalculatorCalculate the peak emission wavelength and radiant exitance of a blackbody from its temperature using Wien's law and Stefan-BoltzmannBragg's Law CalculatorCalculate the Bragg diffraction angle and two-theta from X-ray wavelength, crystal d-spacing, and reflection orderBrewster's Angle CalculatorCalculate the Brewster angle at which reflected light is fully polarized from the refractive indices of two mediaBuffer Capacity CalculatorCalculate the buffer capacity (beta) of an acid-base buffer and the moles of acid or base it can absorb.Buffer pH CalculatorCalculate the pH of a buffer solution using the Henderson-Hasselbalch equation from pKa and component concentrations.Buoyancy CalculatorCalculate buoyant force and whether an object floats using Archimedes' principleCapacitor Energy CalculatorFind the energy in joules and charge in coulombs stored in a capacitor from capacitance in farads and supply voltage. Free, instant.Carbon Footprint CalculatorEstimate your annual carbon footprint in CO2 equivalent from driving, flights, home energy use, and diet choices. Free, instant results.Carnot Efficiency CalculatorFind the maximum theoretical efficiency of a heat engine from hot and cold reservoir temperaturesCarrying Capacity CalculatorCalculate population carrying capacity using logistic growth, including time to reach 50% and 90% of K and a full population time series.Cell Dilution CalculatorCalculate serial dilution steps, dilution factors, and volumes needed to reach a target cell or microbial concentration from a stock solution.Cell Doubling Time CalculatorCalculate cell doubling time, number of generations, and growth rate constant from initial and final cell counts and elapsed timeCentripetal Force CalculatorCompute centripetal force, centripetal acceleration, and orbital speed for any object in circular motion from mass, radius, and speed. Free.Chemical Equation Stoichiometry CalculatorCalculate moles, grams, or molecules of any reactant or product from a balanced chemical equation using stoichiometry.Clausius-Clapeyron Vapor Pressure CalculatorEstimate the vapor pressure of a liquid at a target temperature from a known pressure, temperature, and heat of vaporizationCO2 Breathing Emission CalculatorCalculate the CO2 exhaled by a person through breathing per day, year, or lifetime. Compare to other emission sources and understand the carbon cycle context.Colligative Properties CalculatorCalculate boiling point elevation and freezing point depression from molality, van't Hoff factor, and solvent constantsCombined Gas Law CalculatorSolve the combined gas law P1V1/T1 = P2V2/T2 for any unknown variable between two states of a gas sample. Free, instant results.Combustion Analysis CalculatorDetermine the empirical formula of an organic compound from combustion analysis data (masses of CO2 and H2O collected).Combustion Reaction CalculatorBalance and calculate the stoichiometry of a complete combustion reaction for any hydrocarbon or organic fuel.Compton Scattering CalculatorCalculate the Compton wavelength shift and scattered wavelength of a photon from the scattering angle and incident wavelengthConcentration CalculatorCalculate molarity, mass concentration, or percent concentration of a solution from solute and solvent amounts.Coulomb's Law CalculatorCalculate the electrostatic force between two charges, or solve for charge or separationCyclotron Frequency CalculatorCalculate the cyclotron frequency and angular frequency of a charged particle from its charge, the magnetic field, and its massDalton's Partial Pressure CalculatorCalculate partial pressures and mole fractions for a mixture of gases from the total pressure and moles of each gasDe Broglie Wavelength CalculatorCalculate the de Broglie wavelength of a particle from its mass and velocity, demonstrating wave-particle duality for electrons and protons.Degree of Unsaturation CalculatorCalculate the degree of unsaturation (index of hydrogen deficiency) for an organic molecule from its molecular formula.Density CalculatorCalculate density, mass, or volume using rho = m/V with a built-in reference table of common material densities. Free, instant.Dew Point CalculatorCalculate dew point temperature and heat index from air temperature and relative humidity using the Magnus formula. Free, instant.Diffraction Grating CalculatorCalculate the diffraction angle and grating spacing from lines per millimeter, wavelength, and order using the grating equationDistance Modulus CalculatorCalculate the distance modulus and the distance in parsecs and light-years from a star's apparent and absolute magnitudesDNA Ligation CalculatorCalculate the mass of insert DNA needed for a ligation reaction from vector mass, vector size, insert size, and target molar ratioDoppler Effect CalculatorCalculate the observed frequency shift using the Doppler effect for moving sound sources and observers at any speed. Free, instant.Drag Force CalculatorCalculate aerodynamic drag force from fluid density, velocity, drag coefficient, and reference area using the drag equationElectric Field CalculatorCalculate the electric field and electric potential from a point charge using Coulomb law given the charge and distanceElectricity Cost CalculatorEstimate your monthly electricity bill by entering each appliance's wattage, daily hours of use, and your local kWh rate. Free, instant.Electron Configuration CalculatorFind the full electron configuration and orbital notation for any element by atomic number or symbol.Energy Density of Electromagnetic Fields CalculatorCompute u = ½ε₀E² + B²/(2μ₀) - the volumetric energy density of electric and magnetic fields.Equilibrium Constant CalculatorCalculate the equilibrium constant Keq for a reversible reaction from product and reactant concentrations and their coefficientsFaraday Electrolysis CalculatorCalculate the mass and moles of material deposited during electrolysis from current, time, molar mass, and electrons transferredFaraday's Law CalculatorCompute induced EMF in a coil using Faraday's law of electromagnetic induction: EMF = -N·dΦ/dt.Force CalculatorCalculate force, mass, or acceleration using Newton's Second Law (F = ma), with preset unit conversions between newtons, pounds-force, and dynesFree Fall CalculatorCompute fall height, time, or impact velocity for an object falling from rest under gravity (g = 9.81 m/s²).G-Force CalculatorConvert between linear acceleration (m/s²) and g-force - multiples of standard gravity g = 9.80665 m/s².GC Content CalculatorCalculate the GC content percentage of a DNA or RNA sequence - a key indicator of thermal stability, primer design quality, and genomic composition.Gibbs Free Energy CalculatorCalculate the Gibbs free energy change from enthalpy, entropy, and temperature, and find whether a reaction is spontaneousGraham's Law of Effusion CalculatorCompare the effusion or diffusion rates of two gases using Graham's Law - rate is inversely proportional to the square root of molar mass.Grams to Moles CalculatorConvert between grams, moles, and number of molecules for any element or compound using molar mass.Gravitational Redshift CalculatorCalculate the gravitational redshift and Schwarzschild radius for light emitted near a massive body from its mass and radiusHalf-Life CalculatorSolve remaining amount, elapsed time, or half-life for exponential decay, with the decay constantHardy-Weinberg CalculatorCalculate Hardy-Weinberg genotype frequencies from a dominant allele frequency, including the recessive allele frequency and all three genotypesHeat Index CalculatorCalculate the "feels like" temperature based on air temperature and humidity using the Steadman formulaHenderson-Hasselbalch CalculatorCalculate the pH of a buffer from the pKa and the concentrations of the conjugate base and weak acid using the Henderson-Hasselbalch equationHorizontal Projectile Motion CalculatorCompute range, flight time, and impact velocity for an object launched horizontally from a height.Hydrogen Ion Concentration CalculatorConvert between pH, hydrogen ion concentration [H+], hydroxide ion concentration [OH-], and pOH.Hydrostatic Pressure CalculatorCompute hydrostatic pressure P = ρgh at depth in any fluid, in gauge or absolute pressure.Ideal Gas Law CalculatorSolve the ideal gas law PV = nRT for pressure, volume, moles, or temperature from any three known variables. Free, instant results.Immersed Weight CalculatorCompute the apparent weight of a fully submerged object: actual weight minus buoyant force.Impulse and Momentum CalculatorCompute impulse J = F·Δt = m·Δv and average force from initial/final velocity, mass, and contact time.Ionic Strength CalculatorCalculate the ionic strength of any solution from individual ion concentrations and charges for Debye-Huckel activity calculations. Free.Isoelectric Point CalculatorEstimate the isoelectric point pI of an amino acid from its carboxyl, amino, and side-chain pKa valuesKaya Identity CalculatorDecompose CO2 emissions into population, GDP per capita, energy intensity, and carbon intensity using the Kaya Identity to pinpoint which factors drive growth.Kinetic Energy CalculatorCalculate kinetic energy, mass, or velocity using the KE = ½mv² formula, with unit conversions between joules, calories, and electron-voltsLatent Heat CalculatorCalculate the heat energy for a phase change from mass and specific latent heat, for melting, freezing, boiling, or condensingLens & Mirror Equation CalculatorSolve the thin-lens and mirror equation for focal length, image distance, and magnificationLog Reduction CalculatorCalculate log reduction value, percent kill, and surviving fraction from initial and final microbial counts. Used in disinfection and sterilization validation.Lorentz Force CalculatorCalculate the magnetic Lorentz force on a moving charge from its charge, velocity, magnetic field strength, and angleLotka-Volterra Predator-Prey CalculatorModel predator-prey dynamics using the Lotka-Volterra equations. Calculate equilibrium populations and simulate how prey and predator counts cycle over time.Magnetic Field of a Wire CalculatorCompute B = μ₀·I / (2π·r) - the magnetic field around a long straight current-carrying wire (Ampère's law).Malus's Law CalculatorCalculate the transmitted intensity of polarized light through a polarizer from the incident intensity and the angleMichaelis-Menten Kinetics CalculatorCalculate enzyme reaction velocity from Vmax, the Michaelis constant Km, and substrate concentrationMolality CalculatorCalculate solution molality (mol/kg) and solve for boiling point elevation and freezing point depression.Molar Mass CalculatorCompute the molar mass of any chemical formula with per-element mass percent breakdownMolar Mass of Gas CalculatorCalculate the molar mass of an unknown gas using the ideal gas law from measurable pressure, volume, temperature, and mass.Molarity & Dilution CalculatorSolve molarity from moles or grams, and dilutions with the C1V1 = C2V2 relationshipMolecular Weight CalculatorCalculate the molecular weight (molar mass) of a compound by adding up element atomic masses from the formula.Moment of Inertia CalculatorCalculate the moment of inertia for spheres, cylinders, hoops, and rods from mass and a characteristic dimensionMomentum CalculatorSolve the linear momentum equation p = m times v for momentum, mass, or velocity with unit conversions and collision examples. Free.Nernst Equation CalculatorCalculate electrode or cell potential from standard potential, ion concentrations, and temperatureNet Force CalculatorSolve Newton's second law F = m·a for net force, mass, or acceleration with weight comparison.Net Ionic Equation CalculatorGenerate the complete ionic and net ionic equations for common precipitation, acid-base, and gas-forming reactions.Neutralization CalculatorCalculate the volumes and concentrations needed to neutralize an acid with a base, and the resulting solution pH.Newtonian Gravitational Force CalculatorCalculate the gravitational attraction between two masses in newtons from their masses and the distance between themNormality CalculatorConvert molarity to normality using the n-factor; covers acid-base, redox, and precipitation reactions for chemistry and titration problems.Numerical Aperture CalculatorCalculate the numerical aperture of a lens or optical fiber from the refractive index and acceptance half-angle, with the equivalent f-numberOhm's Law CalculatorApply Ohm's Law (V = IR) to calculate voltage, current, resistance, or power - with unit conversions for electronics and electrical engineering problems.Orbital & Escape Velocity CalculatorCalculate orbital velocity, escape velocity, and orbital period for any planet or custom bodyOsmotic Pressure CalculatorCalculate osmotic pressure using the van't Hoff equation from molarity, van't Hoff factor, and temperature - for ideal solutions in biology and chemistry.Pendulum Period CalculatorCalculate the period and frequency of a simple pendulum from its length and the local acceleration due to gravityPercent Composition CalculatorCalculate the mass percent of each element in a chemical compound from its molecular formula.Percent Yield CalculatorCalculate the percent yield of a chemical reaction from actual and theoretical yields, and identify losses from side reactions, purification, or transfer.pH CalculatorConvert between pH, pOH, hydrogen ion concentration [H+], and hydroxide [OH-] and classify as acidic, neutral, or basic. Free.Photoelectric Effect CalculatorCalculate photon energy, maximum electron kinetic energy, and stopping voltage from wavelength and work functionPhoton Energy CalculatorCalculate the energy of a photon in joules and electronvolts and its frequency in terahertz from the wavelength in nanometerspKa CalculatorConvert between pKa, Ka, pH, and percent dissociation for weak acids and bases with classification and buffer range guidance. Free.Planet Equilibrium Temperature CalculatorEstimate a planet's equilibrium temperature from stellar luminosity, orbital distance, and albedo using the Stefan-Boltzmann radiative balance equation.Potential Energy CalculatorCalculate gravitational potential energy using PE = mgh for any object on Earth or any other planet with a known surface gravity. Free.Power CalculatorCalculate power, work, or time using the formula P = W/t with built-in unit conversions between watts, joules, and horsepower. Free.Pressure at Depth CalculatorCalculate hydrostatic gauge and absolute pressure at depth in water or any fluidProjectile Motion CalculatorCalculate range, maximum height, time of flight, and impact speed for any projectile launched at any angle and speed. Free, instant.Protein Molecular Weight CalculatorEstimate protein molecular weight from amino acid sequence using average residue masses. Returns MW in Da and kDa with amino acid composition.Punnett Square CalculatorGenerate a Punnett square for monohybrid or dihybrid crosses. Shows all genotype combinations, phenotype ratios, and percent probabilities.Radiocarbon Dating CalculatorEstimate the age of an organic sample from its remaining C-14 activity using the radiocarbon decay equation and the standard 5,730-year half-life.RC Time Constant CalculatorCalculate the RC circuit time constant and find the capacitor charge or discharge voltage at any elapsed time. Free, instant results.Reaction Half-Life CalculatorCalculate the half-life of a zero, first, or second order reaction from the rate constant and initial concentrationReaction Quotient CalculatorCalculate the reaction quotient Q from species concentrations and coefficients and predict the direction of a reaction against KRedshift CalculatorConvert redshift to recession velocity and approximate distance using Hubble's lawRelative Humidity CalculatorCalculate relative and absolute humidity from air temperature and dew point using Magnus formulaRelativistic Kinetic Energy CalculatorCompute relativistic kinetic energy KE = (γ-1)mc² for high-speed particles and compare with the classical ½mv² limit.Resistor Color Code CalculatorDecode 4 or 5 band resistor color codes to find the resistance value and tolerance, or look up the color bands for a given resistance. Free.Reynolds Number CalculatorCalculate the Reynolds number from fluid density, velocity, characteristic length, and dynamic viscosity, and find the flow regimeRocket Equation CalculatorCalculate rocket delta-v from specific impulse, initial mass, and dry mass using the Tsiolkovsky rocket equation, with the mass ratioRotational Kinetic Energy CalculatorCompute rotational kinetic energy KE = ½·I·ω² from moment of inertia and angular velocity (rad/s or RPM).Rydberg Spectral Line CalculatorCalculate the wavelength and photon energy of a hydrogen spectral line from the lower and upper electron energy levels using the Rydberg formulaSchwarzschild Radius CalculatorCalculate the Schwarzschild radius of any mass in meters and kilometers, with input in kilograms or solar massesShannon Diversity Index CalculatorCalculate the Shannon diversity index (H'), species richness, evenness (Pielou's J), and Simpson's index from species abundance data.Snell's Law CalculatorCalculate refraction angle and the critical angle for total internal reflection between mediaSolar Panel CalculatorEstimate how many solar panels you need to power your home based on monthly kWh usage, panel wattage, peak sun hours, and system efficiencySound Level (Decibel) CalculatorInterpret decibel levels, hearing damage risk timelines, and ear protection ratingsSpace Travel CalculatorCompute travel time between cosmic distances at constant speed, plus the relativistic proper time onboard.Specific Gravity CalculatorCompute specific gravity (relative density) of a substance against water (1000 kg/m³) or any custom reference fluid.Specific Heat CalculatorSolve Q = mcΔT for heat, mass, specific heat, or temperature change, with material presetsSpeed of Sound CalculatorFind the speed of sound in air by temperature or in other media, with travel time and MachStellar Parallax Distance CalculatorCalculate the distance to a star in parsecs and light-years from its parallax angle using the standard parsec-parallax relationship.Stoichiometry CalculatorConvert between grams and moles and apply mole ratios, with limiting-reagent comparisonStokes' Law CalculatorCalculate the terminal velocity of a sphere settling through a viscous fluid using Stokes' Law - valid for low Reynolds number (Re < 1) creeping flow.Surface Gravity CalculatorCalculate the surface gravitational acceleration of any planet or celestial body from its mass and radius - compare to Earth's 9.8 m/s² standard.Synodic Period CalculatorCalculate the synodic period between two orbiting bodies from their sidereal periods - used to predict planetary oppositions and conjunctions.Telescope Resolving Power CalculatorCalculate a telescope's Dawes and Rayleigh resolution limits in arcseconds from its aperture diameter and the observing wavelengthTerminal Velocity CalculatorCalculate the terminal velocity of a falling object from mass, drag coefficient, and air densityThermal Energy CalculatorCompute heat transfer Q = m·c·ΔT for any substance, or solve for mass or temperature change.Thermal Expansion CalculatorCalculate linear, area, and volumetric thermal expansion from material and temperature changeTime Dilation CalculatorCalculate the Lorentz factor and relativistic time dilation from a velocity given as a percentage of the speed of lightTitration CalculatorCalculate the unknown concentration, volume, or moles in an acid-base titration using the equivalence point relationship.Trihybrid Cross CalculatorCalculate trihybrid cross outcomes for three independent gene pairs. Shows genotype and phenotype probabilities for all eight phenotype classes.Unit Cell Density CalculatorCalculate the theoretical density of a crystalline material from its unit cell type (FCC, BCC, SC), molar mass, and lattice parameter edge length.Van der Waals Gas Pressure CalculatorCalculate the pressure of a real gas using the van der Waals equation with molecular attraction (a) and volume exclusion (b) correction factors.Velocity CalculatorSolve v = d / t for average velocity, distance, or time with km/h and mph conversions.Vertical Exaggeration CalculatorCompute vertical exaggeration (VE) = horizontal scale ÷ vertical scale for topographic profiles and cross-sections.Wave CalculatorCalculate wave speed, frequency, wavelength, and period using v = f-lambda for sound, light, or any periodic wave. Free, instant.Wind Chill CalculatorCalculate the wind chill feels-like temperature from air temperature and wind speed using the NWS formula. Free, instant results.Work CalculatorSolve W = F·d·cos(θ) for work done, applied force, or distance at any angle to the motion.
About Science Calculators
Science calculators apply the formulas that define how the physical world behaves (Newton's laws, the ideal gas law, wave mechanics, energy conservation) without forcing you to remember the constants or chase down unit conversions. The collection covers the core mechanics, thermodynamics, electromagnetism, and chemistry tools that show up in undergraduate courses, engineering reviews, lab work, and curiosity-driven calculations. Constants are taken from the 2019 SI redefinition and the latest CODATA values published by NIST, so the gravitational constant, gas constant, and Avogadro's number match the numbers used in modern physics and chemistry textbooks.
Mechanics is the deepest section. The force calculator solves F = ma in any direction; the kinetic and potential energy tools handle ½mv² and mgh with selectable gravity (Earth 9.81 m/s², Moon 1.62, Mars 3.71, plus the rest of the solar system); and the projectile motion calculator gives range, maximum height, time of flight, and impact speed for any launch angle and initial velocity, accounting for launch height above the landing surface. Wave mechanics solves v = fλ across acoustic, optical, and radio frequencies, with phase speed, period, and wavenumber all derived in parallel.
Thermodynamics and chemistry get the same treatment. The ideal gas law calculator solves PV = nRT for any of the four variables and accepts pressure in Pa, kPa, atm, bar, mmHg, or psi without you having to convert first. The pH calculator works between pH, pOH, [H⁺], and [OH⁻], classifies the solution as acidic, neutral, or basic, and uses Kw = 1.0 × 10⁻¹⁴ at 25 °C as the standard reference. The density calculator includes a built-in materials reference (water 1.000 g/cm³, aluminum 2.70, steel 7.85, lead 11.34) so you can sanity-check measurements quickly.
The environmental and applied tools are increasingly popular. Heat index uses the National Weather Service Steadman polynomial. Wind chill uses the 2001 NWS/Environment Canada formula that replaced the older 1945 Siple-Passel version; dew point uses the Magnus-Tetens approximation accurate to ±0.4 °C between −45 and 60 °C. The carbon footprint calculator pulls EPA and IEA emission factors so the numbers reconcile to government inventories rather than estimates from a green-marketing site. Throughout the category, every calculator shows the equation it solved, the substituted values, and the result with proper SI units, useful both for homework checking and for engineers who want to paste a defensible calculation into a report.
When to Use a Science Calculator
- Solving physics problems involving force, energy, momentum, or wave mechanics
- Working with the ideal gas law (PV = nRT) for chemistry or HVAC calculations
- Calculating pH, pOH, or hydrogen ion concentration for chemistry lab work
- Estimating projectile range or trajectory for sports, ballistics, or design problems
- Computing heat index, wind chill, or dew point for weather or comfort engineering
- Sizing solar panels, decoding resistor color codes, or estimating battery life for electronics projects
Frequently Asked Questions
What value of g (gravitational acceleration) do you use?
Earth's standard gravity is 9.80665 m/s² (the CGPM-defined value), which we round to 9.81 m/s² in display. Calculators that depend on gravity (projectile motion, potential energy, pendulum period) let you select other planetary bodies (Moon 1.62, Mars 3.71, Jupiter 24.79) or enter a custom value for orbital or theoretical work.
Are these formulas accurate enough for engineering work?
Yes for first-pass and academic work. The constants come from CODATA 2018 / SI 2019, and the formulas are textbook-exact. For final engineering design you'd still apply the appropriate safety factors and use specialized FEA or CFD software, but the numbers from these calculators are what those packages converge to under simplifying assumptions.
Why is the ideal gas constant R sometimes 8.314 and sometimes 0.0821?
It's the same constant in different units. R = 8.314 J/(mol·K) when pressure is in pascals and volume in cubic meters; R = 0.08206 L·atm/(mol·K) when pressure is in atmospheres and volume in liters. Our ideal gas calculator picks the right value for the units you choose, so you don't have to remember which is which.
Does the projectile motion calculator account for air resistance?
No. It solves the standard kinematic equations in vacuum. For dense projectiles at modest speeds (a baseball, a thrown rock) the error is small. For low-density or high-speed projectiles (a feather, an arrow, a ballistic round at long range) air drag dominates and you need a numerical ballistics solver instead.
What temperature reference do you use for chemistry calculations?
Standard chemistry calculators use 25 °C (298.15 K) and 1 atm, the IUPAC standard ambient temperature and pressure (SATP). The pH calculator's Kw = 1.0 × 10⁻¹⁴ value is the 25 °C reference; Kw rises with temperature, so neutral pH at 100 °C is closer to 6.13.