What does this beam calculator calculate?
Calculate elastic beam reactions, bending moments, deflection and optional bending stress for two support models. Linear elastic Euler–Bernoulli model with constant E and I. It omits shear deformation, buckling, connections, vibration, load combinations and code design.
Which measurements do you need?
Record clear span (m), uniform downward load (kn/m), downward point load (kn), point distance from left support (m). Check which fields use length, area or a product quantity before entering values.
| Input | Unit / role |
|---|---|
| Clear span (m) | Measured or specified value |
| Uniform downward load (kN/m) | Measured or specified value |
| Downward point load (kN) | Measured or specified value |
| Point distance from left support (m) | Measured or specified value |
| Elastic modulus E (GPa) | Measured or specified value |
| Second moment I (cm⁴) | Measured or specified value |
| Section total depth (mm, optional) | Optional project value |
| User-specified span/deflection denominator (optional) | Optional project value |
Which formula produces the result?
Simple beam: RA = wL/2 + P(L−a)/L; RB = wL/2 + Pa/L; δUDL = 5wL⁴/(384EI). Cantilever: δtip = wL⁴/(8EI) + PL³/(3EI)
Span LLoad P
How does a worked example look?
For a 4 m simply supported span with 2 kN/m, E = 200 GPa and I = 1,000 cm⁴, maximum bending moment is 4 kN·m and midspan deflection is 3.333 mm.
How should you enter units?
Beam inputs use the SI units printed on each field.
Which assumptions affect this estimate?
Linear elastic Euler–Bernoulli model with constant E and I. It omits shear deformation, buckling, connections, vibration, load combinations and code design.
How should you interpret rounding?
Keep unrounded calculations for comparisons. The result displays practical precision; whole pieces and packages round up where applicable. Display rounding is not a measurement tolerance.
Which project details need another check?
Check the actual product specifications, measurement method and project scope. Linear elastic Euler–Bernoulli model with constant E and I. It omits shear deformation, buckling, connections, vibration, load combinations and code design.
How can you compare scenarios?
Calculate a baseline, add it to compare, then change one input and calculate again. The comparison keeps input and result snapshots so you can identify what changed.
Which tools can help with the next step?
Use the Framing, Lumber & Stairs tool directory for related calculations. Keep the scope and units consistent when moving between tools.
