One-Rep Max Calculator
About One-Rep Max Calculator
The one-rep max calculator estimates maximum strength using common Epley and Brzycki formulas.
How to Use
The one-rep max calculator estimates maximum strength using common Epley and Brzycki formulas. Enter the Weight lifted and Reps performed values and review the Epley estimate, Brzycki estimate, and 90% training max outputs after you calculate.
- Open the calculator : Use One-Rep Max Calculator from the Health category.
- Check the inputs : Review the required values and any optional settings.
- Read the formula : Use the formula and notes below to understand how the result is produced.
Common Questions
What does the One-Rep Max Calculator estimate?
It estimates the heaviest weight you may be able to lift for one repetition.
How accurate is the result?
The estimate is less reliable for very high-rep sets, so use it as a training guide rather than a fixed limit.
Is the 1RM calculator accurate for high repetitions?
One Rep Max (1RM) calculators are most accurate when estimating based on a 2 to 5 rep set. Once you enter weights lifted for 10 or more repetitions, the mathematical estimation becomes less accurate because muscular endurance plays a larger factor than raw strength.
Inputs
- Weight lifted
- Reps performed
Outputs
- Epley estimate
- Brzycki estimate
- 90% training max
Formula
Epley 1RM = weight x (1 + reps / 30).