Calculate the frictional force acting on an object, including both static and kinetic friction. This calculator uses the coefficient of friction and normal force to determine the magnitude of the friction force.
Enter your values below
Static friction self-adjusts from 0 up to μsN; kinetic friction stays fixed at μkN once the object is sliding.
Enter μs for the static case and μk for the kinetic case — μs is usually the larger of the two.
Force perpendicular to the contact surface. On a level surface this is the weight, mg.
Optional. Static friction only develops as much as is needed, so it equals the smaller of this and μN.
Optional. Leave the normal force empty to use mg instead, and to report the acceleration of a sliding object.
How this calculator works
Friction force equals the coefficient of friction times the normal force. Use μs for static and μk for kinetic friction.
Common questions about this calculator
These calculators are for educational and informational purposes only. While we strive for accuracy, results should be verified for critical applications. Always consult authoritative sources for engineering or scientific work.
