Estimate the maximum weight you could lift for a single repetition based on a lighter, higher-rep set — no need to risk a heavy single. Get a full percentage breakdown for programming your training.
Estimate the maximum weight you could lift for a single repetition based on a lighter, higher-rep set — no need to risk a heavy single. Get a full percentage breakdown for programming your training. This calculator draws on peer-reviewed, industry-standard formulas used by fitness professionals, dietitians and clinicians worldwide, translated into a fast, easy-to-use browser tool.
Tracking metrics like this over time — rather than relying on a single reading — gives you a much clearer picture of trends in your health and fitness journey. Use this tool regularly alongside our other calculators for a fuller picture of your overall wellbeing.
Testing a true 1RM carries higher injury risk, especially for beginners. Estimating from a submaximal set (e.g. 5-10 reps) is safer and nearly as useful for programming.
We average the Epley and Brzycki formulas, two of the most widely used and researched 1RM estimation equations in strength training.
Accuracy decreases as rep count rises above 10-12, since higher-rep sets are influenced more by muscular endurance than pure strength.