Estimate Your One-Rep Max Without Maxing Out
A one-rep max, or 1RM, is the heaviest weight you can lift for a single repetition. Testing it directly is risky and tiring, so most lifters estimate it from a lighter, safer set. This free calculator does that instantly using three widely accepted formulas: Epley, Brzycki and Lander.
Enter the weight you lifted and how many reps you completed. The tool applies each formula and averages the results into a single estimated max. The estimates are most reliable between one and ten reps, which is exactly where everyday training sets sit.
Below the result you get a full training percentage table. It tells you what to load for different goals, from heavy strength work near 90% of your max down to lighter speed and technique sets, so you can plan your next session straight away.
How to use it
- Enter the weight you lifted and your completed reps.
- Choose kilograms or pounds.
- Tap calculate to see your estimated 1RM and the training table.
Frequently asked questions
How is 1RM calculated from reps?
Formulas such as Epley (weight x (1 + reps/30)) and Brzycki (weight x 36 / (37 - reps)) estimate the maximum weight you could lift for one rep from a lighter set.
How accurate is an estimated 1RM?
Estimates are most accurate for 1 to 10 reps. They are a guide, not a substitute for actually testing a max lift safely.
Should I test a true 1RM?
Only with a spotter, proper warm-up and good form. Many lifters prefer the estimate to avoid the injury risk of a maximal attempt.
What is the training percentage table for?
It shows what weight to load for different goals, such as strength, hypertrophy or speed work, as a percentage of your estimated 1RM.
This tool provides estimates only and is not a substitute for professional coaching. Always lift with good form and a spotter.