Free 1RM calculator

How this 1RM calculator works

It averages two classic formulas: Epley (weight × (1 + reps ÷ 30)) and Brzycki (weight × 36 ÷ (37 − reps)). Averaging dampens the quirks of either alone. The result is rounded to normal plate increments.

Use a set you actually owned. A five-rep PR with clean depth is a better input than a messy eight you barely finished. Re-estimate when your working weights jump, not every Tuesday.

For how Pocket Fit moves load without living inside percentage charts, read reps first, then weight and the progressive overload app comparison.

Frequently asked questions

What is a 1RM?

Your one-rep max is the heaviest load you could lift once with good form. Most people never test it directly. They estimate it from a hard set of three to eight reps and programme off percentages of that estimate.

How accurate is a 1RM calculator?

Epley and Brzycki are solid between about 2 and 8 reps for compound lifts. Past 10 to 12 reps the estimates drift. They also assume the set was close to failure. A casual five is not the same input as a grinding five.

Should I test a true max instead?

Only if you know how to peak, warm up and fail safely. For most lifters, an estimated 1RM from a clean heavy set is enough to set working weights without the injury risk of a naked max.

What percentage should I train at?

Strength work often lives around 80 to 90% for low reps. Hypertrophy main sets often sit around 65 to 80%. Warm-ups are lower. The table on this page is a map, not a law - your recovery and form still decide the day.

Does Pocket Fit use 1RM percentages?

Pocket Fit progresses with a published reps-first rule rather than forcing you to chase a tested max every mesocycle. The calculator is here when you want a number for planning or comparing sessions.