One Rep Max (1RM) Calculator

Estimate your maximum single-rep lift for any exercise — bench press, squat, deadlift, or overhead press. Uses 7 proven formulas and generates a full training percentage table.

Your lift 7 formulas averaged
lbs
reps
Best accuracy at 1–10 reps. Above 15 reps estimates become less reliable.
FAQs
How accurate are 1RM calculators? ›
1RM estimates are most accurate when based on 1–5 rep sets at near-maximal effort. Accuracy decreases as rep count increases — at 10+ reps, estimates can be off by 5–15% depending on the individual. Slow-twitch dominant individuals (endurance athletes) tend to overestimate because they can sustain higher rep percentages; fast-twitch dominant lifters (powerlifters) may underestimate. Always treat the result as an estimate, not a guaranteed max.
What percentages should I use for training goals? ›
General guidelines: 90%+ for maximal strength (1–3 reps), 80–90% for strength (3–5 reps), 70–80% for hypertrophy (6–12 reps), 60–70% for strength-endurance (12–20 reps). The training table above shows these for your specific 1RM. For beginners, working at 60–75% allows learning technique while building strength. Advanced athletes often cycle these intensities periodically.