Free Beam Deflection Calculator
Calculate the maximum deflection of a simply supported beam under a uniform distributed load.
ft
lb/ft
psi
in^4
Max Deflection
0.000 in
Span/Deflection Ratio0
L/360 Limit0.400 in
Max Deflection vs Beam Span
Simply Supported Beam Deflection
Delta_max = 5wL^4 / (384EI)
Where w is the load per inch, L is the span in inches, E is the modulus of elasticity, and I is the moment of inertia. Common deflection limits are L/360 for floors and L/240 for roofs.
Example Calculation
12 ft beam, 200 lb/ft load, E = 1,700,000 psi, I = 98 in^4.
- 01w = 200/12 = 16.67 lb/in
- 02L = 144 in
- 03Delta = 5 x 16.67 x 144^4 / (384 x 1,700,000 x 98)
- 04Delta = 0.283 in
- 05L/360 = 0.40 in; deflection is within limits.
Frequently Asked Questions
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