Your one-rep max (1RM) is the heaviest weight you can lift for a single rep. Here's how to estimate it safely without maxing out.
Testing a true 1RM carries injury risk, especially without a spotter or coach. Formulas like Epley and Brzycki estimate your 1RM from a lighter, safer set — usually 3–10 reps performed close to failure — using the relationship between reps and load.
Epley: 1RM = weight × (1 + reps ÷ 30)
Brzycki: 1RM = weight ÷ (1.0278 − 0.0278 × reps)
Averaging both gives a reasonable middle-ground estimate, since neither formula is perfectly accurate for everyone.
| % of 1RM | Typical Rep Range |
|---|---|
| 90–95% | 2–4 reps (strength) |
| 80–85% | 6–8 reps (strength-hypertrophy) |
| 70–75% | 10–12 reps (hypertrophy) |
Once you have an estimated 1RM, these percentages help structure training blocks around specific goals.
Get your estimated 1RM and a training percentage chart from a recent set.
Open One Rep Max CalculatorThey are most accurate for sets of 10 reps or fewer performed close to failure; accuracy decreases with higher rep counts.
No single formula is perfect for everyone. Averaging the Epley and Brzycki estimates usually gives a reasonable middle-ground figure.
Estimated 1RM is a planning tool, not a guarantee. Work up gradually with a spotter if attempting a true max lift.
Last Updated: July 2026