1RM calculator
Put in a weight and how many clean reps you got. You get your estimated one-rep max and what to load at every percentage, no maxing out needed.
Estimated 1RM114.5kg
Epley116.5kg
Brzycki112.5kg
Percentage table
| % of 1RM | Load | Reps, about |
|---|---|---|
| 100% | 115 kg | 1 |
| 95% | 110 kg | 2 |
| 90% | 102.5 kg | 3 |
| 85% | 97.5 kg | 5 |
| 80% | 92.5 kg | 8 |
| 75% | 85 kg | 10 |
| 70% | 80 kg | 13 |
| 65% | 75 kg | 16 |
| 60% | 67.5 kg | 20 |
| 55% | 62.5 kg | 25 |
| 50% | 57.5 kg | 30 |
Loads are rounded to what you can put on a barbell.
How the estimate works
- Epley: weight × (1 + reps / 30). Tends to read a little high on sets of 6 or more.
- Brzycki: weight × 36 / (37 − reps). Tends to read a little low on the same sets.
- The big number is the average of both. Sets of 2 to 6 reps give the closest estimate; a set of 1 is your actual max.
- The table gives the load for each percentage and roughly how many reps you could get with it from fresh. Leave a rep or two in the tank on working sets.
Questions
- How accurate is a 1RM calculator?
- Within a few percent for most lifters on sets of 2 to 6 reps taken close to failure. Higher reps, sloppy reps or lots of reps left in the tank make it drift. Treat it as a planning number, not a promise.
- Should I test my real one-rep max?
- You don't need to. Training at 70 to 85 percent of an estimated max builds strength with less risk than grinding singles. If you do test, warm up well and use a spotter or safeties.
- Does it work in pounds?
- Yes. Switch the unit to lb and the percentage table rounds to 5 lb jumps instead of 2.5 kg.
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