LiftMath guide

Epley vs Brzycki Formula

How the two most common 1RM formulas differ and when to use each.

The short version

Epley usually gives a slightly more aggressive estimate as reps rise. Brzycki is often more conservative in the common 4-10 rep range. Neither is universally correct because lifters differ in fiber type, technique efficiency, and tolerance for rep work.

When Epley works well

Use Epley when you want a practical training estimate from normal strength work. It is simple, stable, and widely used in strength programming.

It is especially useful when the set was heavy enough to reflect max strength but not so heavy that one missed groove changed the entire result.

When Brzycki is the better default

Use Brzycki when you want to avoid overshooting. This is helpful for lifters starting a new block, managing joint irritation, or estimating lifts where fatigue changes technique quickly.

Compare both before loading a block

If Epley says 265 and Brzycki says 255, the gap is information. Starting a cycle from 255 may let you complete more high-quality work, while 265 may be more relevant for peaking or testing.