Friction Force Calculator
Calculate friction force from coefficient and normal force.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
Can't find what you need?
Request a ToolHow to Use the Friction Force Calculator
Enter the coefficient of friction and the normal force in newtons. The calculator instantly computes the friction force. For an object on a flat surface, the normal force equals the weight (mass times 9.81).
About Friction Force
Friction is a contact force that opposes relative motion between surfaces. It is calculated as the product of the coefficient of friction and the normal force. The coefficient depends on the materials in contact and whether the surfaces are stationary (static) or sliding (kinetic). Friction is essential for walking, driving, and braking. Engineers manage friction through lubrication, material selection, and surface treatment.
Frequently Asked Questions
What is the coefficient of friction?
The coefficient of friction (mu) is a dimensionless number that represents how much friction exists between two surfaces. It depends on the materials and surface conditions. Typical values range from 0.01 (ice on ice) to over 1 (rubber on concrete).
What is the difference between static and kinetic friction?
Static friction prevents an object from starting to move and can vary up to a maximum value. Kinetic friction acts on a moving object and is generally lower than the maximum static friction.
What is the normal force?
The normal force is the perpendicular force exerted by a surface on an object resting on it. On a flat horizontal surface, it equals the weight of the object (mg).