1RM calculator - Estimate your one-rep max for bench, squat, deadlift

Strength training

By Jesús Narváez Tamés · Published on May 11, 2026

Estimate your 1RM (one rep max) from a weight and rep count. 5 formulas (Epley, Brzycki, Lombardi, O'Connor, Lander) and a percentage table.

Units

Weight lifted (lb)

Reps performed

Formula

Estimated 1RM

257.2lb

Percentage table

1 reps
100 %
257.2 lb
2 reps
95 %
241.1 lb
3 reps
92 %
233.8 lb
4 reps
89 %
226.9 lb
5 reps
86 %
220.5 lb
6 reps
83 %
214.3 lb
8 reps
78 %
203.1 lb
10 reps
75 %
192.9 lb
12 reps
70 %
183.7 lb

Max (1-2 reps) (≥90%) Strength (3-5 reps) (80-89%) Hypertrophy (6-12 reps) (70-79%) Volume (60-69%) Endurance (<60%)

Found it useful? Share it

Disclaimer: this calculator provides educational information and estimates based on standard formulas. It is not a substitute for personalised advice from a doctor, nutritionist or trainer. Consult a professional before making significant changes to your diet or training.

Best valueAffiliate link

Optimum Nutrition Micronized Creatine Monohydrate Powder (300 g, unflavored)

The most studied supplement in fitness: it improves performance in short, explosive efforts and supports muscle growth over time. Standard dose 3-5 g/day, no loading phase needed.

Backed by hundreds of studies
Supports strength and muscle size
Excellent value for money

Approx. $19-25View on Amazon →

The 1RM (one-rep max) is the maximum weight you can lift once on a given exercise. It's used to program workouts by percentage and to measure real progress.

Indirect vs direct test

A real max test is only safe if you have ≥ 1 year of experience and a spotter. For everyone else, the estimate from a 3-5 rep set to technical failure (not absolute failure) is accurate enough. The Epley and Brzycki formulas are the most validated.

How to use the percentages

Strength work: 80-95% for 1-5 reps. Hypertrophy: 65-80% for 6-12 reps. Muscle endurance: 50-65% for 15+ reps. But individualise: two people with the same 1RM can have very different rep-weight relationships, especially squat vs bench press.

Frequently asked questions

Which formula is most accurate?+

Epley and Brzycki are the most used and yield similar results up to 10 reps. For very low reps (2-3) use Brzycki; for mid reps (5-8) Epley works well.

Is it safe to do a real 1RM test?+

For beginners, no. Use the calculator with 3-5 reps to technical failure. The real test requires experience, warm-up and a spotter.