One-Rep Max and Smarter Strength Training
Use percentages of your max to plan safe, effective lifting.
What 1RM tells you
Your one-rep max is the heaviest weight you can lift once with good form. It helps you set loads for sets and track progress.
Estimate, do not test
Formulas like Epley and Brzycki predict 1RM from a set of 3 to 10 reps. This avoids the injury risk of true max attempts.
Programming with percentages
Strength work often uses 80 to 90 percent for low reps, and muscle growth uses 65 to 80 percent for 6 to 12 reps. Increase load slowly when you can complete all reps with good form.
Try it: One-Rep Max Calculator
Example with sample values. Open the full calculator →
Estimates are most accurate for sets of 10 reps or fewer. Test true maxes only with a spotter.
Educational content only. This article does not replace advice from a qualified health professional. Medical disclaimer.