One Rep Max Calculator

Estimated 1-rep max (Epley formula), plus target weights for other rep ranges.

Equation used
1RM = Weight × (1 + dfracReps30) — Epley formula

Frequently Asked Questions

What formula estimates my one-rep max?

The Epley formula: 1RM = Weight × (1 + Reps/30), using the weight you lifted and the number of reps you completed.

How accurate is an estimated 1RM vs testing it directly?

Formula-based estimates like Epley's tend to be most reliable for sets of around 10 reps or fewer — they're a useful guide, not a replacement for an actual tested max.

What do the numbers in the rep-range table mean?

Each value is the weight you'd need to lift for that many reps to match your estimated 1RM, using the same Epley relationship solved for weight instead of 1RM.