One Rep Max Calculator
Estimate your one-rep max and the training loads that follow from it
Advanced options
116.7 kg
Estimated 1RM (Epley)
Accuracy is roughly +/-10%, even in the reliable 1-10 rep range.
Compare formulas
116.7 kg
Epley
112.5 kg
Brzycki
117.5 kg
Lombardi
113.7 kg
Lander
112.5 kg
O'Conner
Training loads by percentage of 1RM
| Rep max | % of 1RM | Weight (kg) |
|---|---|---|
| 1RM | 100% | 117.5 |
| 2RM | 95% | 110 |
| 3RM | 93% | 107.5 |
| 4RM | 90% | 105 |
| 5RM | 87% | 102.5 |
| 6RM | 85% | 100 |
| 7RM | 83% | 97.5 |
| 8RM | 80% | 92.5 |
| 9RM | 77% | 90 |
| 10RM | 75% | 87.5 |
Live Results
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Five Formulas
Compare Epley, Brzycki, Lombardi, Lander and O'Conner side by side
Training Load Table
Your 1RM scaled to standard training percentages, rounded to real plate increments
Frequently asked questions
How accurate is a 1RM estimate?
Expect roughly +/-10% even in the reliable 1-10 rep range. These formulas are a training-planning tool, not a substitute for testing your actual max under a bar.
Which formula should I use?
Epley and Brzycki are the most widely used and agree closely for low reps. This calculator shows all five so you can compare, and defaults to Epley as the headline.
Why does the calculator warn me above 12 reps?
Every 1RM formula is derived from data in the roughly 1-10 rep range. Beyond about 12 reps the estimate does not just get less precise, it gets systematically less reliable, so treat it as a rough guide only.
How is the percentage table useful?
It scales your estimated 1RM down to common training percentages (e.g. 5RM at 87%) and rounds each one to a loadable plate increment, so you can use it directly to pick weights for a workout.