It’s widely believed that in the upper portion of a push-up you lift around 69% of your overall body weight, while at the bottom of the movement you are lifting 75%.
These figures can be taken with a grain of salt, but for the most part they’ll give you an accurate indication of how much of your weight you are lifting.
This information can be used to track your progress with pushups, especially if you’re someone who enjoys all the data surrounding working out and getting stronger.