What is a one repetition maximum?

A one repetition maximum is the absolute maximum load you can lift in an exercise only once.

This is a theoretical maximum based on a lighter test load and a small number of repetitions. (This is safer than actually trying to lift a maximum weight)

Example:
If you can bench press 150lbs only 3 times, then you can press 165 only once.

You can then use this number to calculate how much weight you should be using to maximize the effectiveness of an exercise.

Maximum Calculator

What is a one rep maximum?

Why calculate my maximum?

How to perform a maximum test.

When should I test my one repetition maximum?