Is the 2D frame calculator free?

Yes. You can draw a 2D frame, add supports and loads, and get the reactions, free-body diagram and the axial (N), shear (V) and bending-moment (M) diagrams for free, with no sign-up. Creating a free account additionally unlocks the deflected shape and lets you save your model.

Do I need to install anything?

No. The calculator runs entirely in your browser using a WebAssembly finite-element solver — the same engine that powers FERS Cloud. Nothing is uploaded to a server to be solved, so it works offline once loaded.

What can the calculator analyse?

Planar (2D) beams and frames: nodes, members, pinned/roller/fixed supports, point loads, moments and distributed loads. It performs a first-order linear elastic analysis and reports support reactions and internal-force diagrams. Free analyses are limited to 100 members.

How are the bending-moment and shear diagrams calculated?

The frame is solved with the direct stiffness (finite-element) method. Each member's internal forces are sampled along its length to produce continuous N, V and M diagrams. Results match standard beam theory — for example a simply supported beam under a central point load P over a span L gives a peak moment of P·L/4.

Can I see deflections?

The deflected shape and nodal displacements are available once you create a free account. The free, no-sign-up view focuses on equilibrium: reactions, the free-body diagram and the N/V/M force diagrams.

Is this suitable for real structural design?

The calculator is great for learning, checking hand calculations and quick concept design. A free account lets you download the calculation report; for full design — 3D frames, load combinations and Eurocode EC3 steel checks — upgrade to the full FERS Cloud application.

How accurate is 2D frame analysis online compared with a hand calculation?

It solves the same equations. The calculator uses the direct stiffness method, so for cases with a closed-form solution the results agree to within rounding — the worked portal frame example on this site matches the classical pinned-base solution to within 0.04 %. The same model always produces the same reactions and diagrams.

Free 2D Frame Calculator

Run 2D frame analysis online — free, in your browser. Draw your structure, add supports and loads, and get reactions, a free-body diagram and shear, moment and axial diagrams in seconds. No installation, no sign-up to start.

Build a frame now Create a free account

Reactions, free-body diagram and N/V/M diagrams are free. Create a free account to unlock deflections — cloud model storage and sharing are part of Pro.

How to analyse a 2D frame

Step 1
Draw the frame
Pick the Draw tool and click on the canvas. Every click places a node and connects it to the previous one, so a portal frame takes four clicks. Press Esc to finish a run.
Step 2
Add supports & loads
Right-click a node for its support, a point load or a moment; right-click a member for a distributed load.
Step 3
Adjust anything
Drag nodes to move them, click a load arrow to edit it, type exact values in the side panel, and undo with Ctrl+Z.
Step 4
Solve
Run the analysis to get reactions, a free-body diagram and N, V and M diagrams.

Worked example: simply supported beam

A simply supported steel beam (IPE 180) spans 6.0 m with a pin at the left support and a roller at the right. A central point load of P = 1.2 kN acts downward at mid-span. Below are the support reactions, the equilibrium free-body diagram, and the shear-force (V) and bending-moment (M) diagrams produced by the FERS 2D frame calculator.

Reactions: Rₐ = R_b = 0.6 kN (each = P/2). Vertical equilibrium: Rₐ + R_b = 1.2 kN = P.

Constant ±0.6 kN either side of the load, stepping by P at mid-span.

Peak sagging moment M_max = P·L/4 = 1.8 kN·m at mid-span (drawn on the tension side).

Mid-span deflection δ = P·L³/48EI = 1.95 mm. Deflections are unlocked with a free account.

Summary of results
Quantity	Symbol	Value
Support reaction (each)	Rₐ, R_b	0.6 kN
Maximum bending moment	M_max	1.8 kN·m
Maximum shear force	V_max	0.6 kN
Mid-span deflection	δ	1.95 mm

Want a frame rather than a beam? The worked portal frame example solves a 4 m × 3 m portal for reactions, bending moments and deflection — and checks the pinned-base case against the closed-form solution.

Frequently asked questions

Ready for more than 2D?

Create a free account to unlock deflections, or open the full FERS Cloud app for 3D frames, load combinations and Eurocode EC3 steel checks — Pro adds cloud storage and sharing.

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