Free one rep max calculator
Know your max,
without testing it.
Estimate your one-rep max from any set with the Epley and Brzycki formulas, then get a full percentage table of working weights. Free, instant, no signup.
Units
For the most accurate estimate, use a hard set of 3 to 8 clean reps. Estimates drift above 10 to 12 reps.
Estimated one-rep max
115
kg
| % of max | Weight | Typical reps |
|---|---|---|
| 100% | 115 kg | 1 |
| 95% | 109 kg | 2 |
| 90% | 104 kg | 3 to 4 |
| 85% | 98 kg | 5 to 6 |
| 80% | 92 kg | 7 to 8 |
| 75% | 86 kg | 8 to 10 |
| 70% | 81 kg | 10 to 12 |
| 65% | 75 kg | 12 to 15 |
| 60% | 69 kg | 15+ |
Questions, answered
One-rep max, explained.
- What is a one-rep max (1RM)?
- Your one-rep max is the most weight you can lift for a single repetition with good form. It is the standard benchmark for measuring strength and for prescribing training loads as a percentage of your max.
- How is the 1RM estimated?
- This calculator estimates your max from a submaximal set using the Epley and Brzycki formulas and averages them. You enter the weight you lifted and how many clean reps you got, and it projects the load you could handle for a single rep.
- How accurate is an estimated one-rep max?
- Estimates are most accurate for sets of about 2 to 10 reps, usually landing within a few percent of a true max. Above 10 to 12 reps, muscular endurance starts to dominate and the estimate drifts higher than reality.
- How do I use 1RM percentages?
- Most strength programs prescribe loads as a percentage of your 1RM, for example 5 sets of 5 at 80 percent. The table below converts your estimated max into working weights at each percentage so you can plug them straight into a program.
- Should I test a true one-rep max?
- Testing a genuine max is taxing on your nervous system and carries more injury risk, especially without a spotter. Estimating from a solid 3 to 5 rep set is safer and accurate enough for programming for almost everyone.
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