Coefficient of friction calculator

Coefficient of friction = friction force ÷ normal force.

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Friction force magnitude (N)

Normal force (N)

Answer

…

Coefficient of friction = friction force ÷ normal force.

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Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Step-by-step calculation

Inputs are substituted below. Each line evaluates the next operation; intermediate values are displayed to 12 significant digits while the calculation uses full precision.

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Formula and assumptions

For kinetic friction, use a measured sliding force. For static friction, use the maximum force immediately before sliding, not any smaller static force.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Coefficient of friction calculator

Coefficient of friction = friction force ÷ normal force.

For kinetic friction, use a measured sliding force. For static friction, use the maximum force immediately before sliding, not any smaller static force.

Next: Basic calculator

A worked example

With friction force magnitude (n) = 20, normal force (n) = 100, the coefficient of friction is 0.2.

Before you use the result

For kinetic friction, use a measured sliding force. For static friction, use the maximum force immediately before sliding, not any smaller static force.

Example results for friction force magnitude (n)

These examples use Normal force (N): 100. They are reference calculations, not recommended settings.

Friction force magnitude (N)	Coefficient of friction
10	0.1
20	0.2
40	0.4

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