Enter a weight and rep count you can already lift safely, and this one-rep max calculator estimates your 1RM using standard strength formulas, without requiring you to actually test a maximal lift.
One Rep Max (1RM) Calculator
Estimate your maximum lifting capacity safely using scientifically validated strength formulas.
lbs
reps
Training Zone Percentages (% of 1RM)
Working Load Breakdown & Training Targets
| % of 1RM | Estimated Weight | Target Reps / Training Focus |
|---|
This estimate works best in a specific rep range. Our article on finding your true one-rep max without testing it explains why very high rep sets produce less reliable estimates.
Once you have your 1RM, our macro calculator and TDEE calculator can help you set nutrition targets to support your training.