One Rep Max Calculator
Enter a weight you lifted for reps — formulas estimate the true single.
Result
Estimated 1RM114.6 kg
Epley116.7 kg
Brzycki112.5 kg
90% (3–4 reps)90% — 103.1 kg
80% (7–8 reps)80% — 91.7 kg
70% (11–12 reps)70% — 80.2 kg
60% (15–20 reps)60% — 68.8 kg
One Rep Max Calculator — FAQs
How accurate is a 1RM estimate?
Within ±5% at ≤10 reps — beyond ~12 reps estimates drift high. Use sets of 3–8 for the best estimate.
Should I test a true 1RM?
Only if experienced — failure reps under load are injury-prone. Estimates are for programming, not bragging rights.
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