🏋️One Rep Max Calculator

Estimate your 1RM from a working set — no risky max-out needed. Enter the weight you lifted and how many clean reps you did; the calculator runs five validated formulas and builds a training-percentage table instantly.

Unit
kg
Enter a weight and rep count above to estimate your one rep max.

Estimated 1RM

Epley

kg

Brzycki

kg

Lander

kg

Lombardi

kg

O'Conner

kg

Average

kg

Training percentages

% of 1RM Weight Use

1RM estimates are a general reference only — not medical advice. Results are most accurate from sets of 2–6 reps and become less reliable above 10 reps. Always warm up progressively before heavy lifting, use proper technique, and use a spotter for any near-maximal or heavy sets. Lift within your current ability. If you have a heart condition, injury, or any health concern, consult a physician before training at high intensity.

Free One Rep Max Calculator Online

Want to know your max without risking a max-out? Our free One Rep Max Calculator estimates it from a normal working set. As a reliable one rep max calculator, you just enter the weight you lifted and how many clean reps you managed, and it estimates the most you could lift for a single rep — no failed lifts, no spotter, no risk of grinding out a true max alone.

It runs your set through several proven formulas — Epley, Brzycki, Lander, Lombardi, and O'Conner — and shows them side by side plus an average, so you get a balanced estimate rather than one formula's bias. It then builds a training-percentage table from 50% to 95%, with notes on what each band is good for, so you can pick working weights for strength, hypertrophy, or peaking. Switch between kg and lb and label the lift to track progress.

Simply enter your weight and reps to see your estimated max instantly. No sign-up, no downloads, no limits — just clear numbers whenever you need them. Read more on the FAQ or About pages.