Epley vs Brzycki
Both turn a submax set into an estimated one-rep max. We show each and use the average for the % table when Brzycki is valid.
Epley: 1RM = weight × (1 + reps / 30)
Brzycki: 1RM = weight × 36 / (37 − reps)
Brzycki: 1RM = weight × 36 / (37 − reps)
Why 3–10 reps beat 15+
These formulas were built around low-to-mid rep sets. A 15–20 grind is mostly endurance. If the last reps were ugly, the estimate is high.
Using %1RM without a true max
Training percents are a map, not a test day. If you haven’t actually done a 1RM, treat 80% as “challenging doubles/triples,” then adjust. Missed reps beat a spreadsheet ego.
Not medical advice
This tool is for education and planning. It does not diagnose, treat, or replace care from a qualified professional.
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