Specific Gravity Calculator

Find the specific gravity (relative density) of a substance against water at 1000 kg/m³ or any custom reference, and see whether it floats. Free.

Frequently Asked Questions

What is specific gravity?

The ratio of a substance's density to a reference density (usually water at 1000 kg/m³). It is dimensionless.

What is the specific gravity of water?

Exactly 1 when water is its own reference. Pure water at 4 °C is the standard reference for SG.

Does SG predict floating?

Yes - SG < 1 floats in water; SG > 1 sinks. Container shape matters too (boats float despite steel SG > 1).

Is specific gravity the same as relative density?

Yes - they are two names for the same dimensionless quantity: the ratio of a substance's density to a reference density. 'Relative density' is the IUPAC-preferred term; 'specific gravity' is common in engineering and industry. For solids and liquids the reference is pure water (1000 kg/m³ at 4 °C), so this calculator gives both.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.