One-Rep Max Calculator
Estimate theoretical one-rep max strength from a lifted weight and reps.
Epley estimate
215.8 lb
Brzycki estimate
208.1 lb
90% training max
194.3 lb
Formula
Epley 1RM = weight x (1 + reps / 30).
Assumptions
- One-rep max estimates are less reliable for very high-rep sets.
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 : Start with One-Rep Max Calculator.
- Enter values : Fill in the required inputs and any optional settings.
- Review the result : Read the output and use the about page for more detail if needed.
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.