Momentum is conserved in collisions, which lets engineers and physicists predict what happens after impacts.
How to use the Momentum Calculator
- Mass
- Velocity
- Want to work backwards? Type a value into Momentum and Velocity is calculated for you.
Results update as you type, and every field accepts the units shown in its menu.
How it works
Multiply mass by velocity.
Inputs explained
| Field | What to enter |
|---|---|
| Mass | Units: kg, lb, g, oz, st |
| Velocity | Units: m/s, km/h, mph, ft/s, knots |
What each result means
- Momentum = [Mass] × [Velocity]
- Kinetic energy = 0.5×[Mass]×[Velocity]^2
Example values
How the main result changes when Velocity changes and everything else stays at the example values above:
| Velocity (m/s) | Momentum (kg·m/s) |
|---|---|
| 20 | 2.9 |
| 30 | 4.35 |
| 40 | 5.8 |
| 50 | 7.25 |
| 60 | 8.7 |
| 80 | 11.6 |
Formula
p = m × vWorked example
Inputs — Mass: 0.145 kg; Velocity: 40 m/s.
Results — Momentum = 5.8 kg·m/s; Kinetic energy = 116 J.
Frequently asked questions
Is momentum a vector?
Yes, it has direction as well as size.
What is impulse?
The change in momentum, equal to force × time.
What formula does the Momentum Calculator use?
p = m × v.
Can I work backwards from the result?
Yes. Type the result you want into Momentum and the calculator finds the matching velocity.