1RM Calculator

Estimate your one-rep max using the Epley, Brzycki, and Lombardi formulas from any rep count.

Weight lifted

Reps performed Best accuracy at 1–10 reps. Estimates above 15 reps are less reliable.

—

Epley

—

Brzycki

—

Lombardi

—

Average

Rep percentage table (based on Epley)

Reps	% of 1RM	Weight

1RM Calculator

Estimate your one-repetition maximum (1RM) from any weight and rep count using three established formulas.

Epley — weight × (1 + reps / 30) — most widely used
Brzycki — weight × 36 / (37 − reps) — accurate at 1–10 reps
Lombardi — weight × reps^0.10 — tends to give slightly higher estimates
The rep percentage table helps plan training loads at each intensity zone