Science & Engineering

Tension Calculator (Rope & Cable Force in N, kgf, lbf)

Find rope or cable tension in newtons, kilograms-force, and pounds-force. Four scenarios cover a hanging mass, an inclined plane, an Atwood pulley, and a horizontal pull with friction.

How to use
  1. Pick the scenario that matches your setup.
  2. Enter the mass and any angle or acceleration.
  3. Add friction where the scenario needs it.
Scenario
Tension T

enter the load values

In kilonewtons
In kilogram-force
In pound-force
Weight
For study and estimation. Verify against authoritative data before relying on a result.
Was this helpful?

How it's calculated

T = m × (g + a)

T = rope tension (N), m = mass (kg), g = gravity 9.80665 m/s², a = acceleration. Incline: T = m(g sinθ + a + μg cosθ); Atwood machine: T = 2 m₁ m₂ g ÷ (m₁ + m₂).

Common questions

How do I find tension on a hanging mass?

For a still mass, tension equals weight, mg. If it accelerates upward, tension is m times g plus a.

Does tension change on an incline?

Yes. On a frictionless incline the rope holding a mass carries m g times the sine of the slope angle, not the full weight.