1RM calculator
One-rep max calculator: your estimated 1RM
From one set with weight and reps, the calculator estimates your one-rep max (1RM): the weight for exactly one rep. Plus a chart of training weights in percent. Same formula as the berryl app, in kg or lb.
- Free, no sign-up
- Runs only in your browser
- Calculates like the berryl app
How the calculator works
- Epley formula as in the app: 1RM = weight × (1 + reps ÷ 30). With 1 rep, the 1RM is the weight itself. Rounded to 0.1.
- Chart: training weights from 100 to 50% of your 1RM, rounded to 0.5 kg (or 1 lb), with the approximate reps from the same formula in reverse.
- The estimate is most accurate up to about 10 reps. Your real maximum can differ by exercise and person.
An estimate, not training advice: only test your real maximum well warmed up, with clean technique and a spotter, ideally with a training partner or coach.
In the berryl app you log sets with weight and reps for free, and the app spots new records from your estimated 1RM. More on this: Training and nutrition.
More free calculators: Calorie calculator, Protein calculator, Upper limit check, Interaction check. All calculators
Sources
- Epley B. (1985): Poundage Chart. Boyd Epley Workout. Lincoln, NE
- One-repetition maximum (overview of the estimation formulas)
Ready for your day with berryl?
berryl launches on Android first, iPhone follows. Start free, no subscription needed.