One-Rep Max (1RM) Calculator
Estimate your one-rep max from a submaximal set using three proven formulas, then plan training loads from a full %1RM table.
For best accuracy, use a set of 1-10 reps performed close to failure. Formulas get less reliable above 12 reps.
%1RM training-load table
Based on the averaged estimate above. Rep ranges are typical guidelines from common strength-training references, not exact for every lifter.
| % of 1RM | Load | Typical reps |
|---|
Frequently asked questions
How accurate are one-rep max (1RM) estimation formulas?
1RM formulas like Epley, Brzycki, and Lombardi are estimates, not measurements. They are most accurate for sets of 1 to 10 reps performed close to failure. Above 12 reps, fatigue and pacing affect the set differently than a true maximal lift, so the estimate becomes noticeably less reliable.
Which 1RM formula should I use: Epley, Brzycki, or Lombardi?
No single formula is exact for every lifter. Epley tends to estimate slightly higher at higher rep counts, Brzycki slightly lower, and Lombardi falls between them. Averaging all three, as this calculator does, gives a balanced estimate that works well for general programming.
What weight should I use for 80% of my one-rep max?
80% of your estimated 1RM is a common load for strength and muscle-building work, typically trainable for about 7 to 8 reps per set before failure. Use the %1RM training-load table to see the standard rep range for every load from 100% down to 60%.