Estimate your one-rep max.
This uses the Epley formula and then maps common training percentages from the estimate.
Strength Training
1RM Calculator
Use this 1RM calculator to estimate your one-rep max and quickly see working weights for common training percentages.
How it works
How to use the 1rm calculator
1RM Calculator is intended for lifters who want practical training percentages without maxing out constantly. Use it to estimate top-end strength from a set you have already completed safely.
Enter the weight you lifted and the reps you completed with that weight. The calculator returns a estimated one-rep max.
1RM formulas become less reliable as rep count climbs and as set quality or fatigue changes. Use the estimate to guide training, then compare it to how the weights actually move in real sessions.
FAQ
Common questions about this calculator.
Use these quick answers as a starting point, then compare the result to your real-world progress.
What does the 1rm calculator tell me?
Enter the weight you lifted and the reps you completed with that weight. The result is a estimated one-rep max.
How accurate is the 1rm calculator?
1RM formulas become less reliable as rep count climbs and as set quality or fatigue changes.
What should I do after I get my result?
Use the estimate to guide training, then compare it to how the weights actually move in real sessions.
Who is this calculator best for?
This calculator is intended for lifters who want practical training percentages without maxing out constantly.
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