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Enter the weight you lifted and how many reps you completed to estimate your one-rep maximum and see training percentages for each intensity zone.
Live calculator output
Enter weight and reps to calculate your estimated 1RM.
The calculator uses the Epley formula: 1RM = Weight × (1 + Reps ÷ 30). This is the most widely used formula in strength training and is accurate for sets in the 1–10 rep range.
The result is most reliable when performed with sets of 3–8 reps taken close to failure. Sets of 1–2 reps may underestimate true maximum; sets of 10+ reps introduce more estimation error. The calculator also generates a percentage-based training chart so you can immediately apply the result to your programming.
You bench pressed 100 kg for 5 reps: 1RM = 100 × (1 + 5 ÷ 30) = 100 × 1.167 = 116.7 kg, rounded to 117 kg.
Using that 1RM for programming: 90% = 105 kg (heavy singles), 80% = 94 kg (strength work), 70% = 82 kg (hypertrophy), 60% = 70 kg (technique and warm-up sets).
For sets of 3–8 reps performed close to failure, the Epley formula is accurate to within 5–8% of a tested 1RM for most people. Accuracy decreases for sets above 10 reps. Use it as a benchmark for programming, not as a competition record.
Not necessarily. True 1RM testing carries a higher injury risk and requires extensive warm-up. Estimated 1RM from a submaximal set is safer and still precise enough for training purposes.
Hypertrophy research points to 60–80% of 1RM as the effective range for muscle growth, corresponding to roughly 8–15 reps per set. Strength-focused training typically uses 80–90%.
Yes, though it is most commonly used for compound barbell lifts — squat, bench press, deadlift, and overhead press. It works for any loaded movement where you can track weight and reps.
RPE (Rate of Perceived Exertion) on a 1–10 scale indicates how close a set was to failure. An RPE 10 set means you could not have done another rep — those sets give the most accurate 1RM estimates. RPE 7–8 sets (2–3 reps in reserve) will underestimate slightly.
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