Momentum Calculator

Last updated: June 2026

Find

Mass

Mass unitVelocity

m/s

Velocity unit

Momentum

20 kg m/s

Impulse force

Impulse time

Impulse

20 N s

Formula

Momentum p = m x v. Impulse J = F x change in time = change in momentum.

About this calculator

The Momentum Calculator finds momentum, mass, velocity, and impulse for simple physics examples. It helps students connect moving mass, impact examples, and impulse as change in momentum.

Momentum and impulse formulas

Momentum equals mass multiplied by velocity. Impulse equals force multiplied by time and is also equal to change in momentum.

p = m x v
m = p / v
v = p / m
J = F x delta t
J = change in p

How to use the momentum calculator

Choose momentum, mass, or velocity.
Enter the two known values.
Select mass and velocity units.
Use the impulse fields for force over time examples.
Review the main result in SI units.
Compare impulse with change in momentum.

Worked examples

Moving trolley

Input: 2 kg trolley at 10 m/s

Calculation: p = 2 x 10

Result: 20 kg m/s

Impulse

Input: 50 N force for 0.4 s

Calculation: J = 50 x 0.4

Result: 20 N s

Momentum direction

Momentum is a vector in full physics problems. This calculator focuses on magnitude unless signs are entered to show direction.

Conservation of momentum

In a closed system with no external force, total momentum before a collision equals total momentum after the collision.

Simple momentum model

This calculator does not model complex collisions, rotation, deformation, friction, or multi-dimensional vector components.

Frequently asked questions

What unit is momentum?

The SI unit is kg m/s.

What is impulse?

Impulse is force over time and equals change in momentum.

Can momentum be negative?

A sign can indicate direction in one-dimensional problems.

Does speed direction matter?

Yes for vector momentum, though this calculator mainly shows magnitude.

Is momentum conserved?

It is conserved in closed systems without external forces.

Related calculators

force-calculator
speed-calculator
kinetic-energy-calculator

What does this mean?

This calculator is designed to help you understand the likely number before you make a decision or start an application.

Your result should be checked against official UK guidance, especially if your circumstances include dependants, exemptions, prior leave, or a complex immigration history.

Treat the figure as a planning tool rather than legal advice. Where the answer affects an application deadline or major payment, speak to an authorised adviser.