Estimate your true one-rep max
Enter a weight you can lift for multiple reps and get a one-rep max estimate from Epley, Brzycki, Lombardi, Mayhew, O’Conner, Wathan, and Lander formulas — plus training percentages for programming.
Calculator
Estimate your one-rep max from a submaximal set, compare popular strength formulas, and convert the result into training percentages for programming.
Interactive area
Enter the weight and reps you lifted, choose lb or kg, then press Calculate for formula estimates and training loads.
Strength calculator
Formulas used
Epley, Brzycki, Lombardi, Mayhew, O’Conner, Wathan, and Lander. For ≤10 reps we recommend Brzycki; otherwise Epley.
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Supporting context will appear here when content is provided.
Enter a weight you can lift for multiple reps and get a one-rep max estimate from Epley, Brzycki, Lombardi, Mayhew, O’Conner, Wathan, and Lander formulas — plus training percentages for programming.
No single equation fits every lifter. CalcGen shows each formula side by side, recommends Brzycki for ≤10 reps (Epley otherwise), and averages the set for a quick cross-check.
After Calculate, use the percentage table (100% down to 60%) to set working weights for strength, hypertrophy, and endurance blocks.
Submaximal estimates help you plan without grinding a true max. Always warm up, use good form, and treat estimates as guides — not guarantees.
Answers will appear here when FAQ content is provided.
Your one-rep max is the heaviest weight you can lift for a single clean repetition on a given exercise. Coaches use it to prescribe training intensities as percentages of 1RM.
Accuracy depends on the lift, rep range, and lifter. Brzycki is popular for sets of 10 or fewer; Epley is a common general-purpose option. Comparing several formulas (as this calculator does) is usually more useful than trusting one alone.
Sets of 2–10 reps tend to produce the most reliable estimates. Very high-rep sets (15+) drift farther from true maximal strength, so this tool caps input at 36 reps.
Yes. Choose lb or kg before calculating. Results and training loads stay in the unit you selected.
Each row shows a percent of your recommended 1RM and a typical rep range for that intensity — useful for programming warm-ups, working sets, and deload weeks.
No. Formulas estimate capacity from a submaximal set. For competition peaking or exact programming, validate with a well-coached tested single when it is safe to do so.
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