Epley vs Brzycki Formula: Which 1RM Calculator Is More Accurate?

Two formulas dominate one-rep max estimation. Both use the reps-to-failure method, but they give slightly different results — particularly at higher rep ranges.

Epley formula

1RM = weight × (1 + reps/30)

Example: 100kg for 8 reps → 100 × (1 + 8/30) = 126.7kg

Brzycki formula

1RM = weight × 36 / (37 − reps)

Example: 100kg for 8 reps → 100 × 36/29 = 124.1kg

Which is more accurate?

At low rep ranges (1–5), both formulas are very close and reasonably accurate. At higher rep ranges (10+), accuracy degrades for both — neural fatigue and muscular endurance become confounding factors. Most coaches recommend testing with sets of 3–6 reps for best predictive accuracy.

Our 1RM calculator shows results from both formulas side by side.