1RM Calculator
Enter a set you completed to estimate your one-rep max. Use a set you finished with good form, ideally between 2 and 6 reps.
How the estimate works
Epley multiplies the weight by 1 + reps ÷ 30. Brzycki multiplies it by 36 ÷ (37 − reps). Both formulas get less reliable as reps go up.
The Set estimate is the conservative number the Set app uses: it takes the lower of the two formulas and counts any set above 5 reps as a 5-rep effort, so a high-rep set never inflates your max.
Let Set do the math while you train
Log sets in plain text like 5x5 bp 80%, scan percentage or RPE programs into exact loads, and track your estimated max on iPhone and Apple Watch. Private, no account, free to start.
Get Set on the App StoreQuestions
Which 1RM formula is most accurate?
Epley and Brzycki agree closely between 2 and 6 reps. Above that, both drift, so the Set estimate counts higher-rep sets as 5 reps and uses the lower of the two formulas.
Should I test my true 1RM?
An estimate from a hard set of 2 to 5 reps is usually enough to set training percentages. Test a true max only when you are prepared for it and have a spotter or safe bailing setup.