One rep max (1RM) calculator
Estimate your one-rep max from a sub-maximal lift using Epley, Brzycki and other validated formulas. Shows percentage table for programming.
- Free, no sign-up
- No data stored
- Reviewed 2026-01-15
Your details
Results
- Formula epley
- 116.7 lb
- Formula brzycki
- 112.5 lb
- Formula lombardi
- 117.5 lb
- Formula oconner
- 112.5 lb
Training table
| Intensity | Weight | Reps |
|---|---|---|
| 100 % | 114.8 lb | ≈ 1 |
| 95 % | 109.0 lb | ≈ 2 |
| 90 % | 103.3 lb | ≈ 4 |
| 85 % | 97.6 lb | ≈ 6 |
| 80 % | 91.8 lb | ≈ 8 |
| 75 % | 86.1 lb | ≈ 10 |
| 70 % | 80.3 lb | ≈ 12 |
| 65 % | 74.6 lb | ≈ 15 |
| 60 % | 68.9 lb | ≈ 18 |
| 55 % | 63.1 lb | ≈ 22 |
| 50 % | 57.4 lb | ≈ 26 |
Training note
One rm note
About the One Rep Max Calculator
Estimate your one-rep maximum without actually performing a maximal lift. Enter the weight lifted and repetitions completed (up to 12 reps for best accuracy). Multiple validated formulas are compared.
A percentage table shows training loads for common programming schemes (e.g. 5×5 at 80%, 3×8 at 70%).
How to use the One Rep Max Calculator
- Enter the weight lifted.
- Enter the number of reps completed.
- Select a formula or view all.
- Optionally adjust RPE for autoregulation.
- View estimated 1RM and the percentage table.
Frequently asked questions
Which formula is most accurate?
Epley and Brzycki are most widely used and agree closely for 1–10 reps. Accuracy decreases above 10 reps.
Can I use this for any exercise?
Yes, though formulas were validated on compound lifts (squat, bench, deadlift). Isolation exercises may be less accurate.
What is RPE adjustment?
If you did not go to failure, selecting your RPE (rate of perceived exertion) adjusts the estimate. RPE 10 = failure, RPE 8 = 2 reps in reserve.