One Rep Max Calculator
Enter a set you have actually done. Get your estimated 1RM plus the working weights for every percentage you will train at.
Your training percentages
| % of 1RM | Weight | Typical use |
|---|
Reps you should hit at each load
| Reps | Weight |
|---|
Estimates from a submaximal set are most accurate at 5 reps or fewer and drift high above 10. Warm up fully, use a spotter, and never test a true max on a day you are beaten up. General fitness information, not medical advice.
What your one rep max tells you
Your one rep max is the most weight you can move for a single clean repetition. You do not need to test it to use it. Every serious strength program is written in percentages of 1RM, so an accurate estimate from a set you have already done is enough to program months of training without ever grinding a true max.
How the estimate is made
The calculator runs your weight and reps through four established formulas — Epley, Brzycki, Lombardi and O’Conner — and averages them. Averaging smooths out the bias any single formula carries. The estimate is tightest at five reps or fewer and drifts high past ten, so use a heavy set of three to five for the best read.
Training with percentages
Strength work lives at 85-95% for sets of one to three. Your main work sets sit at 80-85% for three to five. Hypertrophy runs 65-75% for six to ten. Speed and technique work stays at 50-60%. The table above converts every one of those into the exact weight on your bar.
Common questions
Should I test a true max? A few times a year at most, and only when sleep, food and recovery are all in place. Estimating from a heavy triple costs you nothing and tells you almost the same thing.
Why do the four formulas disagree? They were built on different lifters and different lifts. The spread shown under your result is the honest range your true max sits inside.
Does this work for every lift? It is most accurate on the big barbell lifts — squat, bench, deadlift and overhead press. Isolation work is far less predictable.
