Momentum Calculator
Calculate linear momentum p = m·v for any mass and velocity in metric or imperial units.
How it works
- 1Enter the object’s mass in kilograms (or pounds) and its velocity in metres per second (or feet per second).
- 2Select metric or imperial — inputs are converted to SI automatically before the calculation.
- 3The calculator applies p = m·v and shows the result in kg·m/s, the SI unit for linear momentum.
Use cases
- Physics students solving collision and impulse problems that need an object’s momentum before impact.
- Engineers estimating the momentum of moving machinery or vehicles to size safety buffers.
- Sports scientists analysing the momentum of athletes or equipment during deceleration.
Frequently asked questions
What is the formula for momentum?
Linear momentum is p = m·v, where p is momentum in kg·m/s, m is mass in kilograms, and v is velocity in m/s. For example, a 2 kg object at 10 m/s has p = 2 × 10 = 20 kg·m/s.
Is momentum a vector or a scalar?
Momentum is a vector — it has magnitude and direction, always in the same direction as the velocity. This calculator reports the magnitude; the direction matches the motion.
Why is momentum shown in kg·m/s even for imperial inputs?
kg·m/s is the universal SI unit for momentum, used in the impulse–momentum theorem (J = Δp) and F = Δp ÷ Δt. There is no common imperial unit, so the tool converts inputs to SI and reports kg·m/s.
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