Physics

Kinetic Friction Calculator

Friction force and deceleration on a surface.

Enter your values

Enter the mass in kg.

Enter the coefficient of friction you are working with.

Enter the surface angle in degrees.

Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.

Results
Friction force
147.2 N
Normal force
490.5 N
Deceleration
2.94 m/s²

Quick answer

Friction force = coefficient of friction x normal force.

Ff = mu x N

At a glance

What it doesFriction force and deceleration on a surface.
CategoryPhysics
Inputs neededMass, Coefficient of friction, Surface angle
Main outputFriction force
FormulaFf = mu x N
CostFree — no sign-up, no download

How to use the Kinetic Friction Calculator

  1. 1Enter the mass of the sliding object.
  2. 2Enter the coefficient of kinetic friction for the surface pair.
  3. 3Add a slope angle if the surface is inclined.

Inputs explained

Mass(kg)
Enter the mass in kg.
Coefficient of friction
Enter the coefficient of friction you are working with.
Surface angle(degrees)
Enter the surface angle in degrees.

Worked example

Using the values the calculator loads with:

Inputs

  • Mass50 kg
  • Coefficient of friction0.3
  • Surface angle0 degrees

Results

  • Friction force147.2 N
  • Normal force490.5 N
  • Deceleration2.94 m/s²

Frequently asked questions

Where do I find the friction coefficient?

Standard tables give typical values, e.g. rubber on dry concrete is about 0.6-0.8.

Static vs kinetic friction?

Static friction (higher) resists starting motion; kinetic friction applies once sliding.

What do I need to enter into the Kinetic Friction Calculator?

Just 3 values: mass, coefficient of friction, surface angle. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.

How does the Kinetic Friction Calculator work out the answer?

Friction force = coefficient of friction x normal force. It applies the formula Ff = mu x N and shows the working so you can check each step by hand.

Is the Kinetic Friction Calculator free, and do I need an account?

It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.

Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.