One Rep Max (1RM) Calculator
Calculate your estimated one rep max from any weight and rep count. Uses four proven formulas.
Estimated 1RM
262 lbs
Epley
263 lbs
Brzycki
253 lbs
Lombardi
264 lbs
Mayhew
268 lbs
Training Percentage Chart
100%262 lbs1 reps
95%249 lbs2-3 reps
90%236 lbs3-4 reps
85%223 lbs5-6 reps
80%210 lbs7-8 reps
75%196 lbs9-10 reps
70%183 lbs11-12 reps
65%170 lbs13-15 reps
60%157 lbs16-20 reps
Frequently Asked Questions
What is a 1RM?+
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's used to set training percentages and track strength progress.
Which 1RM formula is most accurate?+
Brzycki and Epley are the most commonly used and tend to be accurate for 1-10 reps. All formulas become less accurate above 10 reps. For best accuracy, test with a weight you can lift for 3-5 reps.
How do I use my 1RM for training?+
Common training zones: Strength: 80-90% for 3-5 reps. Hypertrophy: 65-80% for 8-12 reps. Endurance: 50-65% for 15-20 reps. Power: 50-70% for 3-6 explosive reps.