Your one-rep max, without risking the attempt
Estimate your 1RM — the most weight you could lift once — without having to risk actually testing it. Enter the weight and reps of a set you completed and we compute your 1RM with the three most-used formulas, plus a table of training loads by percentage.
Estimate using the Epley, Brzycki and Lombardi formulas. Most reliable with sets of 1-5 reps. Never test a true 1RM without warming up and, ideally, a spotter.
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How is 1RM calculated?
Your one-rep max is the heaviest weight you could lift once with good technique. You do not have to test it to know it: with the weight you lifted and the number of reps you managed, a handful of validated equations estimate it well. We show three — Epley, Brzycki and Lombardi — because they disagree slightly and the spread between them is the honest margin of error. All three are most accurate below about 10 reps; past that the estimate drifts, because endurance starts to matter more than maximum strength. Under the result you get the percentage table, which is what you actually program your training from.
1RM percentage chart and reps
How many reps come out at each percentage of your max, and what each band is good for. It is an average: bench press usually yields fewer reps at the same percentage than squat or deadlift, because fewer muscle groups are involved.
| % of 1RM | Reps | What it trains |
|---|---|---|
| 100 % | 1 | Maximal strength |
| 95 % | 2 | Maximal strength |
| 90 % | 4 | Strength |
| 85 % | 6 | Strength |
| 80 % | 8 | Hypertrophy |
| 75 % | 10 | Hypertrophy |
| 70 % | 12 | Hypertrophy |
| 65 % | 15 | Muscular endurance |
Classic load-repetition relationship from the National Strength and Conditioning Association. It shifts with the exercise and with individual training experience. These are reference ranges for healthy adults, not a diagnosis or individual advice.
FAQ
What is 1RM?
The maximum weight you can lift for a single repetition with correct technique. It is the reference strength programmes are written against: most sets are prescribed as a percentage of it rather than as an absolute weight, so it travels with you as you get stronger.
Do I have to attempt a real 1RM to know it?
No, and for most people it is not worth it. A true max attempt is technically demanding, needs a spotter and carries real injury risk. Estimating from a set of 3-8 reps taken close to failure gets you within a few percent, which is plenty for programming.
What percentage do I use for muscle or for strength?
Broadly: strength lives at 85-95% for 1-5 reps, hypertrophy at 65-80% for 6-12, and muscular endurance below 65%. These bands overlap far more than most programmes suggest — total hard sets matter more than landing on an exact percentage.
How often does my 1RM change?
For a beginner it can move every few weeks; the more trained you are, the slower it moves. Re-estimate every 4-8 weeks or whenever a working set feels clearly easier than it should. It also fluctuates day to day with sleep, food and stress, sometimes by 5%.