One-Rep Max Calculator
Estimate your one-rep max from any set you've completed, using the Epley and Brzycki formulas, plus a full percentage table to program your training.
One-Rep Max Calculator
Enter a weight you've lifted and how many reps you completed
Formula estimates are most accurate between 1–10 reps
Your Estimated 1RM
Complete the form to estimate your 1RM
Epley and Brzycki estimates plus a training table
Most strength programs prescribe loads as a percentage of your 1RM. Estimating your 1RM from a working set lets you build those percentages without risking a maximal single.
True 1RM attempts carry a higher injury risk and demand several days of recovery. A formula estimate from a 3–5 rep set gives you nearly the same programming value with far less fatigue.
- 50–60%Warm-ups, technique work, and deload weeks — high reps, low fatigue.
- 65–75%Hypertrophy volume and most accessory work — 8–12 rep sets.
- 80–90%Strength building — 3–5 rep sets with full rest between sets.
- 90–100%Peak strength and singles — keep these sessions low-volume and well rested.
Safety Note
Lifting heavy is risky without proper technique, a spotter, or safety pins. Start conservatively, warm up thoroughly, and never sacrifice form to hit a number. This calculator provides estimates for educational purposes only.