FullCalculator

One Rep Max Calculator

Estimate 1RM

Enter the weight lifted and reps completed (2-12 reps for best accuracy)

Formula

Brzycki: 1RM = W × 36/(37-R) | Epley: 1RM = W × (1 + R/30)

Frequently Asked Questions

What is a one rep max?
Your 1RM is the maximum weight you can lift for a single repetition with proper form. It's used to program training percentages. You can estimate it from a set of multiple reps instead of actually maxing out.
Which 1RM formula is best?
Brzycki and Epley are most common. Both are accurate for 2-10 reps. Above 10 reps, accuracy decreases. This calculator averages both formulas for a better estimate.

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