Science Calculators

Friction Force Calculator

Enter a mass, incline angle, and coefficient of friction to calculate the normal force and friction force.

Normal force

98.10 N

Friction force

29.43 N

Normal force is N = mg·cos(θ) for an object on an incline (θ = 0° for flat ground). Friction force is F = μN — this gives the maximum static or kinetic friction depending on which coefficient you enter.

How to use this tool

  1. 1Enter the object's mass.
  2. 2Enter the incline angle (0° for flat ground).
  3. 3Enter the coefficient of friction.
  4. 4See the normal force and friction force.

Frequently asked questions

Should I use the static or kinetic coefficient?+

Use the static coefficient to find the force needed to start motion, or the kinetic coefficient to find the friction force while already sliding — they're usually different values for the same surfaces.

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