You don’t have to risk a true max attempt to know your strength. Enter a recent set and get a reliable estimate of your one-rep max, plus the training percentages that go with it.
How this works
Your one-rep max (1RM) is estimated from the weight you lifted and the reps you completed, averaging three well-known formulas:
- Epley: weight × (1 + reps ÷ 30)
- Brzycki: weight × 36 ÷ (37 − reps)
- Lombardi: weight × reps0.10
The formulas are most accurate for sets of 3–10 reps taken close to failure. The table shows common training percentages of your estimated max.
Stop exercising and rest if you feel pain, dizziness or unusual shortness of breath. Check with your doctor before starting a new exercise program.
