Free tool

One Rep Max Calculator

Estimate your 1RM from a submaximal set, then read the working percentages you can actually programme against.

Your set

Weight liftedkg

The load on the bar, including the bar.

Reps completedclean reps only

Count only reps you completed with good form and without help.

Formula

Average of all threeSmooths the disagreement between formulas. Recommended.defaultEpleyw × (1 + reps / 30). Most common in strength training.1985Brzyckiw × 36 / (37 − reps). Slightly lower at high reps.1993Lombardiw × reps^0.1. Runs higher on long sets.1989

Working loads

Round to loadable weightson

RoundExact

Rounds down, never up — a set you cannot load is worse than one that is slightly light.

Smallest incrementkg

2.5 kg5 kg1 kg

a pair of 1.25s

Estimated one rep max

115,5kg

from 100 kg × 5 reps

By formula

epley116,7 kg

brzycki112,5 kg

lombardi117,5 kg

Working sets

rounded down to 2.5 kg

% of 1RM	Load (kg)	Reps
100%	115	~1
95%	107,5	~2
93%	105	~3
90%	102,5	~4
87%	100	~5
85%	97,5	~6
83%	95	~7
80%	90	~8
77%	87,5	~9
75%	85	~10
70%	80	~12

This is an estimate from a submaximal set, not a tested max. Warm up properly, and do not attempt a true 1RM without a spotter or safety pins.