One Rep Max Calculator

Estimate one-repetition maximum from a submaximal lift and repetition count.

Preparing One Rep Max Calculator

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Input

Enter the lifted weight, the number of good-form repetitions you completed, and the calculator will estimate a one-rep max. This tool shows the result instantly without step-by-step output.

Input summary

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How to use One Rep Max Calculator

Provide the weight and rep count from a recent set, and the calculator will estimate the top single-rep strength behind that effort.

What this calculator is for

This calculator is for training progression, program planning, and strength benchmarking when you want a one-rep-max estimate without attempting a true maximal lift that day.

Tips

Use a set performed with solid technique, because sloppy reps can inflate the estimate.
Most one-rep-max equations work best with lower repetition counts than with very high-rep sets.
An estimate is useful for planning loads, but it is still different from a safely tested true max.