One Rep Max Calculator
Calculate your one rep max (1RM) from a set you've already lifted, with a full percentage table for training loads.
Training loads from your 1RM
Weights are based on the Epley estimate.
| % of 1RM | Weight | Typical reps |
|---|---|---|
| 95% | 88.7 kg | 1โ3 |
| 90% | 84.0 kg | 1โ3 |
| 85% | 79.3 kg | 3โ6 |
| 80% | 74.7 kg | 3โ6 |
| 75% | 70.0 kg | 6โ10 |
| 70% | 65.3 kg | 6โ10 |
| 65% | 60.7 kg | 10โ15 |
| 60% | 56.0 kg | 10โ15 |
| 55% | 51.3 kg | 10โ15 |
| 50% | 46.7 kg | 10โ15 |
One rep max is estimated rather than measured, so it carries a few per cent of error even with a perfect set. Epley (1985) is reported as the headline figure because it stays stable across a wider rep range; Brzycki is shown alongside for comparison and is best between 2 and 10 reps. Never test a true single rep without a spotter and a proper warm-up.
Frequently asked questions
How do I calculate my one rep max?
Lift a weight you can manage for a set of several reps, then apply a formula. The Epley equation used here is weight ร (1 + reps รท 30), which is accurate for sets of about ten reps or fewer.
How accurate is a 1RM calculator?
Estimates are most reliable for sets of five reps or fewer and drift as the rep count climbs. These numbers are for planning training loads, not for competition attempts.
How do I use my 1RM for training?
Multiply your estimated max by a percentage. Training at 70 to 80% of 1RM is typical for building strength with manageable volume, while 85% and above is used for heavier, lower-rep work.
Related calculators
Heart Rate Calculator
Calculate your maximum heart rate by age and your target training zones for fat burning, aerobic and peak effort.
VO2 Max Calculator
Estimate your VO2 max from the Cooper 12-minute run test or a resting heart rate, and see how your aerobic fitness compares by age.
Compound Interest Calculator
Calculate compound interest growth on savings or investments. See how your money compounds monthly, quarterly or yearly, with a full balance schedule.
Mortgage Calculator
Estimate monthly mortgage payments, total interest and a full amortization schedule. Compare rates, terms and down payments instantly.