1RM · plate math · workout tracker
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Enter a weight and reps to estimate your one-rep max (averaged Epley & Brzycki), see training percentages, and load the bar with the right plates — all free, in your browser.
Estimate it from a weight you can lift for a known number of reps. Gym Log averages two proven formulas — Epley (weight × (1 + reps ÷ 30)) and Brzycki (weight × 36 ÷ (37 − reps)) — then shows a training-percentage table. Enter the weight and reps in the 1RM tab. Estimates are most accurate at 1–10 reps.
Subtract the bar weight from your target, divide by two, and load the largest plates first. The Plates tab does this automatically: enter the target total and pick your bar (lb or kg) and it lists the exact plates per side.
It is an estimate, not a measured max. Rep-based formulas are most accurate in the 1–10 rep range, usually within a few percent of a true one-rep max; above 10 reps they drift high. Averaging Epley and Brzycki reduces the error of either one alone.
A standard Olympic barbell is 45 lb (20 kg). Women's Olympic bars are 35 lb (15 kg); many technique bars are 15 lb (7 kg). Set the bar to match what you actually load so the per-side math is exact.
Yes — free on the web, no account, no ads, and it runs entirely in your browser, so your sets never leave your device. Unlike subscription trackers there is nothing to sign up for. An optional one-time Pro unlock in the app adds unlimited logging and export.
More free tools from KunStudio.