One Rep Max Calculator
Estimate your one-rep max from a weight and rep count using the Epley, Brzycki, and Lombardi formulas. Free 1RM calculator with the average.
Independently verified for accuracy
Calculator by Toolsloft ↗- Estimated 1RM (average)
- 259.97
- Epley
- 262.5
- Brzycki
- 253.13
- Lombardi
- 264.29
Estimate your one-rep max, the most weight you could lift for a single rep, from a set you have already done. Enter the weight and the number of reps and the calculator returns three published estimates plus their average, which is useful for setting training percentages without testing a true max.
How this is calculated
It uses three standard 1RM formulas: Epley (weight x (1 + reps/30)), Brzycki (weight x 36 / (37 - reps)), and Lombardi (weight x reps^0.10), then averages them. The estimates are most accurate at low reps and drift apart as reps climb, which is why an average is shown.
How to use
- Enter the weight you lifted.
- Enter how many reps you completed with it (1 to 36).
- Read the Epley, Brzycki, and Lombardi estimates and their average.
Examples
- 225 for 5 reps:
about 260 one-rep max - 135 for 10 reps:
about 177 one-rep max
FAQ
- How accurate is a 1RM estimate?
- Estimates are closest when the set is in the 1 to 6 rep range. Past about 10 reps the formulas diverge more, so treat higher-rep estimates as rough.
- Why three formulas?
- Epley, Brzycki, and Lombardi each fit the strength-endurance curve a little differently. Showing all three and the average gives a more honest range than any single number.
- Should I test a true one-rep max instead?
- A true max is the most accurate but carries more injury risk and needs a spotter. Estimating from a 3 to 5 rep set is safer for most lifters and accurate enough to set training weights.