Reps-to-failure Calculator

Enter a weight and select the maximum number of reps you can lift it (1-10). The table will show what weight you can lift for different numbers of reps to failure (RTF) as predicted by the formulas of various researchers.

For example, suppose you can lift to failure a weight of 108kg for 10 reps. Brzycki's formula predicts your 1‑RM will be 144kg, whereas O'Conner's predicts it will be 135kg.

Weight (kg or lb):   Max. reps:

RTFBrzyckiEpley LanderLombardiMayhew O'ConnerWathenAverageAverage
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