One rep max (1RM) calculator
Estimate your 1RM from any set and get a rep-max table for programming.
Estimated 1RM
116.7 kg
Epley formula
| Reps | Weight | % 1RM |
|---|---|---|
| 1 | 116.5 kg | 100% |
| 2 | 109.5 kg | 94% |
| 3 | 106 kg | 91% |
| 5 | 100 kg | 86% |
| 8 | 92 kg | 79% |
| 10 | 87.5 kg | 75% |
| 12 | 83.5 kg | 71% |
How this was calculated: Epley: 1RM = weight × (1 + reps ÷ 30). Most accurate from sets of 3–8 taken close to failure.
Estimates for healthy adults, not medical advice. If you are pregnant, have a medical condition or a history of disordered eating, speak to a qualified professional first.
Worked example
100kg for 5 reps gives an estimated 1RM of about 116.7kg (100 × (1 + 5/30)). A rough 8-rep weight would be about 92kg.
Common questions
- How accurate is an estimated 1RM?
- Estimates are most accurate from sets of 3–8 reps taken close to failure. Above about 12 reps they become unreliable, so this calculator caps the estimate there.
- Do I need to test a true 1RM?
- Not to build strength or muscle. Tracking your estimated 1RM over time shows progress without the fatigue and risk of maximal attempts.
- Why do different calculators give different answers?
- They use different formulas (Epley, Brzycki and others). Use one consistently so changes reflect real progress.
Track every estimated 1RM and PR automatically.
6 Pack Club starts from these numbers, then learns from what you actually log — and tells you why every time it changes something.
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