One-rep max calculator
Enter the weight and the reps of a hard set. You get your estimated 1RM and the load to use at every common training percentage, without having to test a true max.
Training loads
| % of 1RM | Load | Reps (approx.) |
|---|---|---|
| 100% | 115 kg | 1 |
| 95% | 110 kg | 3 |
| 90% | 102.5 kg | 5 |
| 85% | 97.5 kg | 6 |
| 80% | 92.5 kg | 8 |
| 75% | 85 kg | 10 |
| 70% | 80 kg | 12 |
| 65% | 75 kg | 14 |
| 60% | 70 kg | 15 |
| 50% | 57.5 kg | 19 |
Estimates from published population formulas, not a measurement or medical advice. Talk to a doctor or dietitian before a big change in diet or training, especially with a health condition.
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Questions
How is the one-rep max estimated?
It averages two standard formulas, Epley and Brzycki. Epley tends to overestimate at higher reps and Brzycki to underestimate, so the average is steadier across 2–10 reps.
How many reps should I use?
A set of 3 to 6 hard reps gives the most accurate estimate. Past 10 to 12 reps, endurance matters more than strength and every formula drifts.
Should I test a true 1RM?
Most people never need to. Training at 70–85% of an estimated max builds strength with far less risk, and the estimate updates every time your sets get heavier.