FBD Builder

Place each force on the body at its point of application, watch the free-body diagram draw itself, then resolve the components, sum the moments about O, and check full rigid-body equilibrium — instantly. Perfect for beams, brackets, levers, and concurrent-force problems.

🆓 Free interactive tool — build and resolve as many diagrams as you like · Balance … EP

① How it works

Moments are summed about the origin O (the centre of the grid). Use consistent units — e.g. forces in N with positions in m, or forces in kN with positions in m. Angle convention: 0° points right (+x), measured counter-clockwise — so 90° is up, 180° is left, 270° (or −90°) is down. The point of application (x, y) is measured from O in your length unit; leave both at 0 for a force acting through O (a concurrent / particle problem).

② Add a force

Label

Magnitude

Angle (°)

Point x

Point y

③ Free-body diagram

Add a force above to start your diagram

🧲

No forces yet. Add one above, or tap Load example to see a loaded beam.

📐 Results

Net force ΣFₓ

—

Net force ΣFᵧ

—

Moment ΣM about O

—

Resultant magnitude

—

Resultant direction

—

Line of action from O

—

Component & moment breakdown

Force	Mag	Angle (°)	x	y	Fₓ	Fᵧ	M about O
Σ (net)	—	—	—	—	—	—	—