1RM calculator
Estimate your one-rep max (1RM) from a normal set, without a max test, then see which loads to use for each rep range.
| % of 1RM | Load | Possible reps |
|---|
How it works
The more reps you can do with a load, the lower that load is as a percentage of your max. The Epley formula (1RM ≈ load × (1 + reps ÷ 30)) is the one PrimeFeat uses to detect your records on every set; Brzycki (1RM ≈ load ÷ (1.0278 − 0.0278 × reps)) is shown for comparison. Full explanation: how to calculate your 1RM.
FAQ
How do I calculate my 1RM without testing it?
Do a set close to failure with a load you can lift 2 to 10 times, then apply the Epley formula: 1RM ≈ load × (1 + reps ÷ 30). Example: 100 kg × 8 reps gives about 127 kg.
Which 1RM formula is the most accurate?
Epley and Brzycki give similar results up to 10 reps. Beyond that, the error grows; stay between 3 and 8 reps for an accurate estimate. Big lifts (bench press, squat, deadlift) estimate better than isolation exercises.
What is a percentage of 1RM used for?
To program intensity without a max test: 70 to 80% of 1RM for 8 to 12 reps, 85% and above for strength work in the 1 to 5 rep range.
In PrimeFeat, your estimated 1RM is recalculated on every set, records are flagged live and your strength curve is shown per exercise.
Open the app → Download on the App Store
Sources
- LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. J Strength Cond Res. 1997;11(4):211-213. scholar.google.com/scholar?q=The+accuracy+of+prediction+equations+for+estimating+1-RM+performance+in+the+bench+press%2C+squat%2C+and+deadlift
A training estimate, not medical advice.