The push-up test from "The Canadian Standardized Test of Fitness" rates your upper body strength based on the number of push-ups you can perform
1. Do some light warm-up for your arms and shoulders
2. Perform as many push-ups as you can
3. Females perform the test with the knees touching the ground, males with toes touching the ground (see pictures)
4. Enter age, gender and number of push-ups into the calculator.
When performed under standardized conditions this test can be considered quite reliable, but note that results will be negatively correlated with body weight.
Niemann DC 1995. Fitness and sports medicine: a health-related approach. 3rd ed. Mountain View, CA: Mayfield