One Rep Max Calculator
Estimate your one-rep max (1RM) from the weight and reps you lifted using the Epley and Brzycki formulas. Includes a training percentage table from 60–95%.
Estimated One-Rep Max
212lb
average of Epley & Brzycki
Epley
216 lb
Brzycki
208 lb
| % of 1RM | Weight | ~Reps |
|---|---|---|
| 95% | 201 lb | 2 |
| 90% | 191 lb | 4 |
| 85% | 180 lb | 6 |
| 80% | 170 lb | 8 |
| 75% | 159 lb | 10 |
| 70% | 148 lb | 12 |
| 65% | 138 lb | 15 |
| 60% | 127 lb | 18 |
Estimates are most accurate for sets of 10 reps or fewer. Always warm up and use a spotter for heavy attempts.
Frequently Asked Questions
What is a one-rep max (1RM)?
Your one-rep max is the maximum weight you can lift for a single repetition of an exercise with good form. It's the standard measure of maximal strength and the basis for percentage-based training programs.
How do you calculate one-rep max?
This calculator estimates 1RM from a submaximal set using two well-known formulas. Epley: 1RM = weight × (1 + reps/30). Brzycki: 1RM = weight × 36 / (37 − reps). Both are most accurate for sets of about 10 reps or fewer.
Which is more accurate, Epley or Brzycki?
They agree closely at low reps and diverge as reps climb. Brzycki tends to give slightly lower estimates at higher reps. For sets under 10 reps either is fine; the average of the two is a reasonable working number.
How do I use the training percentage table?
Strength programs prescribe loads as a percentage of 1RM. For example, 5×5 strength work often sits around 80–85% of 1RM, while hypertrophy work uses 65–75%. Use the table to pick a working weight for your target rep range.
How often should I test my one-rep max?
Testing a true 1RM is taxing and carries injury risk, so most lifters estimate it from rep maxes instead and only test directly every few months, if at all. Re-estimate whenever your rep performance improves.