Friction Calculator: Force and Coefficient
This friction calculator uses F = ฮผN to find the force of friction. Enter the coefficient of friction and the mass of the object in pounds or kilograms, add a slope angle if the surface is tilted, and it finds the normal force and the friction force in newtons and pounds-force. It also tells you whether the object will slide down the slope on its own. A second mode works backward: enter the friction force and normal force to find the coefficient. A table of typical static and kinetic coefficients helps you pick a realistic value for physics problems.
Friction Calculator
Friction force from the coefficient and normal force, on flat ground or an incline.
How to use the Friction Calculator
- Choose to find friction force or the coefficient.
- Enter the coefficient, mass and slope angle, or the two forces.
- Read the normal force and friction force in N and lbf.
Friction formula
F = ฮผ × N. On a slope of angle ฮธ, N = m × g × cos ฮธ and the downhill pull is m × g × sin ฮธ.
Features
- F = ฮผN solver
- Flat surface or incline
- Mass in lb or kg
- Finds the coefficient of friction
- Shows if the object slides
- Typical ฮผ values table
Frequently asked questions
What is the formula for friction?
Friction force = coefficient of friction × normal force, F = ฮผN. On flat ground, N equals the weight, m × g.
How does a slope change friction?
On an incline the normal force is m × g × cos ฮธ, so friction gets smaller as the slope gets steeper.
What is the difference between static and kinetic friction?
Static friction holds a resting object in place and is usually higher. Kinetic friction acts once the object is sliding.
What is a typical coefficient of friction?
Rubber on dry concrete is about 0.7 to 1.0, wood on wood about 0.25 to 0.5, and steel on ice about 0.03.
Will an object slide down a ramp?
It slides when tan ฮธ is greater than the static coefficient. The tool compares the downhill pull with the maximum friction.