One-rep max (1RM) calculator
Estimate your one-rep max from a recent hard set, then read off the weight for any rep count or percentage.
Use a set of 10 reps or fewer, stopped within a rep or two of failure.
Estimated one-rep max
116.7kg
Epley formula. Brzycki: 112.5 kg.
- 3 reps
- 106kg
- 5 reps
- 100kg
- 8 reps
- 92kg
| Reps | Weight |
|---|---|
| 1 | 116.5 kg |
| 2 | 109.5 kg |
| 3 | 106 kg |
| 4 | 103 kg |
| 5 | 100 kg |
| 6 | 97 kg |
| 7 | 94.5 kg |
| 8 | 92 kg |
| 9 | 89.5 kg |
| 10 | 87.5 kg |
| 11 | 85.5 kg |
| 12 | 83.5 kg |
| % of 1RM | Weight |
|---|---|
| 100% | 116.5 kg |
| 95% | 111 kg |
| 90% | 105 kg |
| 85% | 99 kg |
| 80% | 93.5 kg |
| 75% | 87.5 kg |
| 70% | 81.5 kg |
| 65% | 76 kg |
| 60% | 70 kg |
| 55% | 64 kg |
| 50% | 58.5 kg |
Load any of these with the plate calculator.
The 1RM formulas: Epley and Brzycki
Both formulas convert one set's weight and reps into an estimated single:
- Epley: 1RM = weight × (1 + reps ÷ 30)
- Brzycki: 1RM = weight × 36 ÷ (37 − reps)
The result uses Epley, the formula VERTEX uses, with Brzycki alongside. The two agree within a few percent up to about 10 reps and diverge after that.
How accurate is a 1RM estimate?
Prediction equations are most accurate for sets of about 10 reps or fewer. Above 12 reps this calculator holds the 12-rep estimate.
All of them assume the set ended close to failure. Stop well short and the estimate reads low, but if you stop at the same point every time, the trend is still real. More in what your estimated 1RM is actually telling you.
Rep-max table and percentage chart
The rep-max table runs the formula in reverse; the percentages suit programmes written as “4 × 6 at 75%”. Treat both as starting points. To see how your max compares, use the strength standards or DOTS calculator.
One-rep max FAQ
What is a 1RM?
The heaviest weight you can lift for one full repetition with good form. It is the standard measure of strength and the basis for percentage-based training loads.
Which 1RM formula is the most accurate?
None is best for everyone. Epley and Brzycki agree within a few percent for sets of up to about 10 reps, where prediction equations are most accurate. Use the same formula every time so your numbers stay comparable. VERTEX uses Epley.
Is the estimate accurate for the deadlift?
Less so. Tested against real maxes, the common equations predicted the bench press and squat well but tended to underestimate the deadlift. Treat a deadlift estimate as a minimum.
Do I need to test my real max?
Only if you compete. A true max attempt gives one data point at the cost of heavy fatigue and some risk. A hard set of 3 to 8 reps is enough to set loads and track progress.
Why is the estimate capped at 12 reps?
Epley adds weight for every extra rep without limit, so a set of 50 would predict an unrealistic max. Above 12 reps the calculator holds the 12-rep estimate, as the VERTEX app does.
Sources
- Epley B. Poundage Chart. Boyd Epley Workout. Lincoln, NE: Body Enterprises; 1985.
- Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance. 1993;64(1):88–90.
- LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research. 1997;11(4):211–213.
Built by Max Van Strydonck, Founder of VERTEX. Last reviewed .