Epley & Brzycki formulas · full %1RM training table
Your one-rep max (1RM) is the heaviest weight you can lift for a single rep of an exercise with good form. It's the standard benchmark for tracking strength over time and for programming workouts as a percentage of your max (e.g. "5 reps at 80% of 1RM"). Testing it directly is risky at near-maximal loads, so most lifters estimate it instead — lift a lighter, safer weight for a few reps to failure, and this calculator works backward from that to estimate your true 1RM.
Your set
For best accuracy, use a set of 10 reps or fewer, taken close to failure.
These are formula-based estimates, not a substitute for a supervised 1RM test. Always warm up properly and use a spotter or safety equipment for near-maximal lifts.
How it works
Enter the weight and reps from a recent set, ideally taken close to failure.
We apply two formulas — Epley and Brzycki — and average them for your estimated 1RM.
We generate a full percentage table so you know exactly what weight corresponds to 60-100% of your max, useful for programming sets and reps.
Formula accuracy decreases with higher rep counts. A 3-5 rep set generally gives a more reliable estimate than a 12-15 rep set.
Frequently asked questions
By using a formula that predicts your 1RM from a lighter set you can safely complete for multiple reps, using the relationship between weight lifted and reps performed. This calculator uses the Epley and Brzycki formulas.
Both estimate 1RM from a submaximal set using slightly different math. Epley tends to estimate slightly higher for higher rep counts, while Brzycki tends to be more conservative. Averaging both gives a reasonable middle estimate.
Most accurate for sets of 10 reps or fewer. Accuracy drops off for higher rep sets, since the relationship between weight and fatigue becomes less linear. For best accuracy, use a set of 1-5 reps taken close to failure.
Strength programs often prescribe a percentage of your 1RM for a given number of sets and reps (e.g., "3 sets of 5 at 80%"). The table shows the actual weight for each percentage, so you can load the bar correctly.
Generally no — true 1RM testing carries higher injury risk and requires good technique under maximal load. Most lifters are better served by estimating 1RM from submaximal sets, especially early in training.