Friction force calculator
Enter the friction coefficient and mass; leave the angle at 0 for a flat surface. The weight component along the slope is shown too.
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How to use it
- Enter friction coefficient μ, mass, surface angle and gravitational acceleration g.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
N = m × g × cos θ, F = μ × N, weight component along the slope = m × g × sin θ.
Example
Inputs: Friction coefficient μ = 0.5, Mass = 10 kg, Surface angle = 0 degrees, Gravitational acceleration g = 9.80665 m/s². Result: Friction force: 49.0332 N; Normal force: 98.0665 N; Weight component along the slope: 0 N.
Limits and caveats
- Friction coefficients are measured and vary with surface condition, so use a value suited to your materials.
- With a static coefficient the result is the maximum friction before sliding starts, not always the actual friction.
Questions about this tool
What is the difference between static and kinetic friction?
Static friction stops an object from starting to move; kinetic friction acts while it slides. The static coefficient is usually higher, which is why starting a push is hardest.
When does an object slide down a slope on its own?
When the weight component along the slope exceeds maximum static friction, that is when tan θ is greater than the static coefficient.
Does friction depend on contact area?
In the simple model, no. It depends only on the normal force and the coefficient.