One Rep Max Calculator
Estimate your one-rep max (1RM) from a set you can do for multiple reps. Most accurate for 2-10 reps. Above 10 reps, estimates get less reliable.
The weight you can lift for the given reps with good form.
Reps to technical failure (couldn't do another with good form).
Unit
Display unit only — calculation is unit-agnostic.
Estimated 1RM (average of three formulas)
257 lb
Practical (rounded to plates): 255 lb
Epley
263 lb
w × (1 + reps/30)
Brzycki
253 lb
w × 36 / (37 - reps)
Lander
256 lb
100w / (101.3 - 2.67r)
Training intensities (% of 1RM)
| % 1RM | Weight | Typical reps |
|---|---|---|
| 95% | 245 lb | 2 |
| 90% | 230 lb | 3-4 |
| 85% | 220 lb | 5-6 |
| 80% | 205 lb | 7-8 |
| 75% | 195 lb | 9-10 |
| 70% | 180 lb | 12 |
| 65% | 165 lb | 15 |
| 60% | 155 lb | 16-18 |
| 50% | 130 lb | 20+ |
Educational tool only — not a training prescription. Always warm up properly. Don't test 1RM in a single workout — the calculator is meant to estimate from existing performance, not encourage maxing out. Use a spotter for heavy lifts. Stop if anything feels wrong.