FREE ATHLETIC UTILITY
Adaptive 1RM & Strength Calculator
Calculate your estimated one-rep max and exact percentage-based training loads across power, strength, and hypertrophy zones.
Lift Parameters
5 reps
1 (1RM)5 (Strength)10 (Hypertrophy)15
Formula Comparison:
Epley Formula:117 kg
Brzycki Formula:113 kg
Lombardi Formula:117 kg
O'Conner Formula:113 kg
Estimated 1-Rep Max
115 kg
Blended Epley + Brzycki model • Max accuracy under 10 reps
Prescribed Training Zones
100%
RPE 10.0~1 rep115 kg
95%
RPE 9.5~2 reps109 kg
90%
RPE 9.0~3 reps104 kg
85%
RPE 8.5~5 reps98 kg
80%
RPE 8.0~8 reps92 kg
75%
RPE 7.5~10 reps86 kg
70%
RPE 7.0~12 reps81 kg
65%
RPE 6.5~15 reps75 kg
1RM & Strength Calculator FAQ
How to use one-rep max projections safely in your workout periodization.
1RM is estimated using proven formulas like Epley and Brzycki. By testing a submaximal weight for 2 to 10 repetitions, the calculator projects your theoretical 1-rep ceiling without the injury risk of a true single-rep test.
Adaptive 1RM • FitSchool Beta
Stop Doing Gym Math On Your Phone Notes
FitSchool Track automatically adjusts your working sets, target reps, and warm-up jumps in real time based on your bar speed and daily fatigue.