🧲 Friction Calculator
Calculate the force of friction between two surfaces from the normal force and the coefficient of friction.
What friction force is
Friction is the resistive force between two surfaces in contact that opposes relative sliding motion. It is proportional to the normal force pressing the surfaces together, scaled by a coefficient of friction that depends on the materials involved.
The formula used
This calculator uses F = μN, where μ is the coefficient of friction and N is the normal force. On a flat, level surface, N equals the object’s weight (m·g); on an angled surface, N is reduced to m·g·cos(θ), which this calculator accounts for.
The coefficient of friction is a measured, material-dependent value found in reference tables (for example, roughly 0.3–0.6 for wood on wood, or 0.7–1.0 for rubber on dry concrete). This calculator does not distinguish static from kinetic friction; enter whichever coefficient is relevant. For general physics education purposes.