One Rep Max Calculator
Estimate one rep max from your measurements.
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What this tool does
Estimate one rep max from your measurements. Prediction from submaximal repetitions, not a safe maximal lifting recommendation.
How to use the One Rep Max Calculator
- Enter or select lifted weight in lb.
- Enter or select repetitions completed.
- Read the calculated result; change any measurement to compare alternatives.
Formula
Epley=weight×(1+reps/30); Brzycki=weight×36/(37−reps); one rep returns actual weight
- weight
- Lifted weight (lb, before metric conversion)
- reps
- Repetitions completed
Prediction from submaximal repetitions, not a safe maximal lifting recommendation.
Worked example
For one rep max calculator, the following measurements illustrate the exact method: Lifted weight: 135; Repetitions completed: 5.
Inputs
- Lifted weight135 lb
- Repetitions completed5
Result
- Epley estimated 1RM157.5 lb
- Brzycki estimated 1RM151.88 lb
Results explained
- Epley estimated 1RM
- Epley estimated 1RM from the formula above, expressed in lb before metric conversion. Prediction from submaximal repetitions, not a safe maximal lifting recommendation.
- Brzycki estimated 1RM
- Brzycki estimated 1RM from the formula above, expressed in lb before metric conversion. Prediction from submaximal repetitions, not a safe maximal lifting recommendation.
Frequently asked questions
Epley=weight×(1+reps/30); Brzycki=weight×36/(37−reps); one rep returns actual weight
Prediction from submaximal repetitions, not a safe maximal lifting recommendation.
No. These are general-information estimates, not diagnosis, treatment, fertility advice or exercise clearance. Consult a qualified health professional.
Individual physiology, measurement technique and health conditions may cause large differences from model estimates.
No. BAC estimates never establish that driving is safe or legal; do not drive after drinking.