Momentum Calculator

Linear momentum is an object's mass multiplied by its velocity, written p = m times v. It is measured in kilogram meters per second and points in the same direction as the velocity, so it is a vector quantity.

Impulse is the force applied multiplied by the time it acts, J = F times t, measured in newton seconds. By the impulse-momentum theorem it equals the change in an object's momentum, which is why a newton second and a kilogram meter per second are the same unit.

Yes. Momentum takes the sign of the velocity, so motion in the direction you have chosen as negative gives a negative momentum. Mass itself is always positive, which is why the tool rejects a zero or negative mass.

Rearrange to v = p divided by m. Set Solve for to velocity, enter the momentum and the mass, and the result keeps its sign so you can read direction as well as speed.

Use m = p divided by v. Choose Solve for mass and enter the momentum and velocity. Velocity cannot be zero here, since dividing by zero has no answer, and the resulting mass must come out positive.

SI units throughout: mass in kilograms, velocity in meters per second, momentum in kilogram meters per second, force in newtons and time in seconds, so impulse comes out in newton seconds.

No. It works with the momentum of a single object. Conservation of momentum in a collision needs the momenta of both objects before and after, which is a separate calculation you would do by hand or with a collision tool.

Impulse is force multiplied by time, so one without the other is undefined. Enter both to get a result, or leave both blank to skip the impulse and just solve the momentum relationship.

Values are rounded to nine decimal places, which is effectively exact for everyday inputs. That precision means clean inputs like 2 kilograms and 3 meters per second return a tidy 6, with no floating-point noise.