Calculate the coefficient of friction (static or kinetic) from normal force and friction force, or using mass and acceleration.

μ = 0.3000

Formula: μ = F_f / N. Static friction acts before motion; kinetic friction acts during sliding. Typical values: Steel on steel 0.15–0.6, Rubber on concrete 0.6–0.85.

What is the Coefficient of Friction?

The coefficient of friction (μ) is a dimensionless scalar that describes the ratio of the force of friction between two surfaces to the normal force pressing them together .

μ = F_f / N

Where:

• F_f — friction force (N)
• N — normal force (N)

There are two types of friction coefficients:

• Static friction (μ_s): acts before motion begins. It is usually higher than kinetic friction .
• Kinetic friction (μ_k): acts during sliding motion. It is typically lower than static friction .

Typical coefficient values :

• Steel on steel: 0.15 – 0.6 (dry), 0.02 – 0.1 (lubricated)
• Rubber on concrete: 0.6 – 0.85 (dry)
• Wood on wood: 0.25 – 0.5
• Glass on glass: 0.1 – 0.3
• Ice on ice: 0.02 – 0.09

How to Use This Calculator

1. Select calculation mode: Choose “From Force (F, N)” or “From Mass & Acceleration (m, a)”.
2. Select friction type: Static (before motion) or Kinetic (during sliding).
3. Enter values: For “From Force” mode — input normal force and friction force. For “From Mass” mode — input mass, acceleration, and gravity.
4. Calculate: Click the “Calculate” button or press Enter.
5. Reset: Use the “Reset” button to restore default values.
6. Interpretation: The result shows the coefficient of friction with an interpretation guide. Higher values indicate rougher surfaces with more grip .