Free tool

One-rep max (1RM) calculator

Enter the weight and the reps of a hard set to estimate your one-rep max, without testing a true max. Add your bodyweight to see your strength-to-bodyweight ratio.

Last reviewed October 9, 2026

Calculate your 1RM

Weight liftedRepsUnitBodyweight (optional)

Estimated 1RM116.7 kgBrzycki: 112.5 kg

Training loads
% of 1RM	Load	≈ Reps
100%	116.7 kg	1
95%	110.8 kg	1
90%	105 kg	3
85%	99.2 kg	5
80%	93.3 kg	7
75%	87.5 kg	9
70%	81.7 kg	12
65%	75.8 kg	16
60%	70 kg	20

Estimates only. Calculated in your browser; nothing is sent.

How the estimate works

The calculator uses the Epley formula: 1RM = weight × (1 + reps ÷ 30). It's the same formula Repvoice uses for your estimated 1RM per lift. For comparison, it also shows the Brzycki estimate, which tends to come out a little lower at higher reps.

Estimates are most reliable from sets of 10 reps or fewer taken close to failure.
Use a set with clean technique. A grinding rep with a broken form isn't a fair input.
Different lifts and different people fit the formulas differently. Treat the number as a guide, not a test result.

How to use your 1RM in training

Many programs prescribe loads as a percentage of your 1RM. The table under the calculator shows each percentage and roughly how many reps you could do at that load (the Epley formula in reverse). For example, sets of 5 are often programmed around 80–85%, and sets of 8–12 around 65–75%.

Track it without the spreadsheet

Repvoice calculates your estimated 1RM per lift from every set you log, week by week, with every PR marked. Your Lifter Card turns it into a 1–99 rating for chest, back, legs, shoulders, arms and core, relative to your bodyweight. It's an estimate from the sets you log, not a test.