The standard unit of angular momentum is the Newton meter second, or the kilogram meter squared per second squared. Angular momentum can also be measured in Joule seconds.

Angular momentum is defined as the vector position of a particle relative to its origin times the linear momentum of the particle. It can be measured in particles or objects that are in circular motion. Objects that rotate at a constant velocity have the same angular momentum at each point in their rotation due to the law of conservation of momentum. The product of angular momentum is analogous to the product of linear momentum.