A free online beam calculator that works like a real tool
This beam calculator is built for engineers, students, fabricators and DIY builders who need fast, accurate structural answers without installing software or creating an account. It runs a complete Euler–Bernoulli finite-element solver directly in your browser, so results appear instantly as you type. There are no load limits, no locked features, and no signup form: open the page and analyze.
Whether you call it a simple beam calculator, an online beam calculator, or a structural analysis tool, the workflow is the same: set a beam length, place supports, add loads, and read the diagrams. The drag-and-drop canvas lets you move supports and loads like a real editor, and every change re-solves in under a millisecond.
What this beam calculator can analyze
Beam types
Simply supported beams, cantilevers, fixed–fixed beams, propped cantilevers, overhanging beams, multi-span continuous beams, and Gerber beams with internal hinges (moment releases). If you are searching for a cantilever beam calculator or a simply supported beam calculator, those configurations are one click away in the examples menu.
Supports and connections
Pin, roller, fixed and spring supports can be placed anywhere along the beam, including at overhangs. Spring stiffness is fully adjustable, and you can prescribe support settlement to study differential settlement effects. Internal hinges create true moment releases between spans, which is essential for modeling Gerber girders.
Loads
Add unlimited loads: concentrated point loads, applied moments, uniform distributed loads, triangular loads, and general linearly varying (trapezoidal) loads with independent start and end intensities. Loads can start and end anywhere on the beam, and a self-weight toggle automatically applies the beam’s weight as a distributed load from the section area and material density.
A steel beam calculator and a wood beam calculator in one
Material and section libraries make this tool equally useful as a steel beam calculator and a wood beam calculator. Presets include structural steel (A36), aluminum (6061-T6), concrete and timber, each with realistic Young’s modulus, density and yield strength. The section library covers rectangles, hollow sections, circles, I-beams, channels, and a curated set of common AISC W-shapes, and you can always enter a custom area and moment of inertia by hand. For ridge beam sizing in roof framing, model the ridge as a simply supported or overhanging timber beam with rafter point loads: the calculator reports reactions, maximum moment and deflection so you can compare the result to allowable-span tables.
Results you can actually use
A results dashboard surfaces the maximum shear, maximum moment, maximum deflection and maximum bending stress with the exact location of each, so you never have to hunt through a chart. Below it, interactive shear force, bending moment, slope and deflection diagrams let you hover or tap to read values at any point along the span. Deflection-limit badges check your beam against the common L/240, L/360 and L/480 serviceability limits automatically.
Everything is built for real workflows: full metric and imperial unit systems with granular unit pickers (mm, cm, m, in, ft; N, kN, lb, kip; Pa, MPa, GPa, psi, ksi), a sign-convention toggle, undo and redo, shareable links that encode the entire model in the URL, CSV export of all diagram data, and a print-optimized report you can save as PDF.
How to use the beam calculator
- Set the beam length and pick a preset from the examples menu, or start from scratch.
- Click the beam to add supports and hinges; drag glyphs to reposition them.
- Add loads from the input panel: point loads, moments, UDLs, triangular or trapezoidal loads.
- Choose a material and cross-section, or enter custom properties.
- Read reactions and maximum values from the dashboard; hover the diagrams to query any point.
- Share the link, download the CSV, or print the report for your records.
Why engineers choose this free beam calculator
Most free tools cap the number of loads, hide deflection results behind a paywall, or push you into a signup funnel. This one does not. It handles statically indeterminate structures, continuous spans, spring supports, internal hinges and support settlement for free, and it keeps your data private because every calculation happens locally on your device. Bookmark it, share it, and use it as your everyday online beam calculator.
Looking for theory? The beam formulas page lists closed-form reactions, moments and deflections for the standard cases, and the guide explains how to read shear and moment diagrams. Ready to start? Open the calculator.
Frequently asked questions
What is a beam calculator?
A beam calculator computes reactions, shear force, bending moment, slope and deflection for a beam under given supports and loads. This tool uses an exact finite-element method and returns piecewise-exact diagrams.
Is this beam calculator really free?
Yes: unlimited loads, unlimited spans, all materials and sections, export and printing. No account is ever required.
Can I use it as a wood or steel beam calculator?
Yes. Pick steel, aluminum, concrete or timber presets, or enter a custom modulus. W-shapes are included for steel, and rectangular sections cover typical lumber sizes.
Which beam types are supported?
Simply supported, cantilever, fixed–fixed, propped cantilever, overhanging, continuous multi-span and Gerber beams with internal hinges, plus spring supports and settlement.
Can I share or save my model?
Yes. The model is encoded in the URL, so copying the link shares the exact beam. Your last model is also auto-saved in the browser.
How do I calculate the load on a beam?
Add up every load the beam carries: dead loads (self-weight of the beam, floor, roof, finishes), live loads (occupancy, snow, furniture), and concentrated loads from walls or equipment. Multiply floor loads in kN/m² by the tributary width to get a line load in kN/m, then enter it here. The calculator returns reactions and internal shear and moment along the span.
What is the formula for beam calculation?
For a simply supported beam with a central point load: R = P/2, Mmax = PL/4, δmax = PL³/(48EI). With a uniform load w: R = wL/2, Mmax = wL²/8, δmax = 5wL⁴/(384EI). Cantilever with tip load: M_max = PL at the wall, δ_tip = PL³/(3EI). Full reference on the formulas page.
How do I calculate how much weight a beam can hold?
Run two checks and take the lower answer. Strength: keep bending stress σ = M·c/I below the allowable stress (yield ÷ safety factor). Serviceability: keep deflection δmax ≤ L/360 (or L/240). Enter your section, read M_max and δ_max from the dashboard, and compare σ_max to the material’s allowable stress.
How do I calculate structural load capacity?
Capacity combines bending, shear and deflection. Bending: the largest P such that M_max ≤ fy·I/c. Shear: V_max ≤ τ_allow·A. Deflection: choose E·I so δ_max ≤ L/limit. This tool reports all three with locations, so each check is a direct read-off; code design (AISC, NDS, Eurocode) additionally applies resistance factors.