One Rep Max Calculator

Your one rep max is the maximum weight you can lift for a single repetition with proper form. It's used to set training percentages and track strength progress.

The Epley and Brzycki formulas are considered most accurate for reps under 10. For higher rep ranges (10+), the Wathan and Mayhew formulas tend to be more reliable. This calculator shows all seven for comparison.

Common training zones: 90-100% for maximal strength (1-3 reps), 75-85% for strength/hypertrophy (4-8 reps), 65-75% for hypertrophy (8-12 reps), and 50-65% for endurance (12+ reps).

Using the One Rep Max Calculator is simple: visit the tool page, enter your data or input into the provided fields, and get instant results. Follow the controls on the page. Some functions require sign-in or a paid plan; see Pricing for limits.

The Free plan includes 10 tool uses per day. Some features require an account or a paid plan. Check the controls on the tool page and Pricing for the applicable limits.

The One Rep Max Calculator returns results based on the inputs and the tool methodology. Check assumptions, units and source dates. Treat projections as estimates. For critical decisions, always consult a qualified professional.

Yes, the One Rep Max Calculator is fully responsive and works perfectly on smartphones, tablets, and desktop computers. Simply open NexTool in your mobile browser and navigate to the tool — no app download required.