Estimate your one-rep max from a set you can do, plus a training percentage chart.
Your one-rep max (1RM) is the most weight you can lift for a single clean repetition. It's the standard way to measure strength and to set training loads. Since testing a true 1RM is risky, this calculator estimates it from a lighter set of several reps.
Two common formulas are used here. The Epley formula is weight × (1 + reps ÷ 30), and the Brzycki formula is weight × 36 ÷ (37 − reps). They give slightly different numbers — that's normal. Both are most accurate when the set is about 10 reps or fewer.
Training programs often call for a percentage of your 1RM. Heavy strength work sits around 85–95%, general strength and size around 70–85%, and lighter endurance work around 50–65%. Find the percentage for the rep range you're training and use the matching weight as a starting point.
These are estimates from the Epley and Brzycki formulas — most accurate at about 10 reps or fewer. Warm up and use a spotter for heavy attempts. This is general fitness information, not coaching.