Beam Deflection Calculator

w = 500/12 = 41.67 lb/in, L = 144 in, E = 1,600,000 psi, I = 230.8 in^4. delta = 5*41.67*144^4/(384*1600000*230.8) = 0.63 in. L/360 = 0.40 in - fails; L/240 = 0.60 in - fails.

L/360 = (16*12)/360 = 192/360 = 0.533 inches.

Yes. A center point load produces about 60% more deflection than the same total load uniformly distributed over the same span. Third-point loads fall between the two.

Most LVL manufacturers specify E = 1,700,000 to 2,000,000 psi. Use the value from the product's engineering data sheet. A common default is 1,900,000 psi.

Use uniform distributed load for joists and beams carrying a uniformly loaded floor or roof. Use center point load for a beam carrying a concentrated load such as a post. Third-point loads model two-point loads such as a beam supporting another beam at each third of the span.

Select any listed beam size to auto-fill the moment of inertia I. The I values used are: 4x6=48.5 in^4, 4x8=111.1 in^4, 4x10=230.8 in^4, 4x12=415.3 in^4, 6x8=174.7 in^4, 6x10=362.7 in^4, 6x12=652.6 in^4 (calculated from actual dimensions).

Continuous beams deflect less than simply supported beams (roughly 4x less for two equal spans). This calculator is for simply supported single-span beams only.

This is a planning and learning tool. Structural design for permitted construction must be performed or reviewed by a licensed engineer.