justyourcalculatorOne Rep Max Calculator
Estimate your one-rep max and your training weights.
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One Rep Max Calculator
Estimate your 1RM and training weights
Estimated one rep max
215.8 lb
From 185 lb × 5 reps (Epley)
- Epley
- 215.8 lb
- Brzycki
- 208.1 lb
- Lombardi
- 217.3 lb
- O'Conner
- 208.1 lb
- Lander
- 210.4 lb
- Mayhew
- 220.2 lb
- Wathen
- 215.7 lb
Most accurate from sets of 3 to 6 reps taken close to failure. Always lift heavy singles with a spotter.
How it was calculated
- Epley: 1RM = w × (1 + reps / 30) = 185 × (1 + 5 / 30) = 215.8
- Brzycki: 1RM = w × 36 / (37 - reps) = 185 × 36 / 32 = 208.1
| % of 1RM | Weight | Typical reps |
|---|---|---|
| 100% | 215.8 lb | 1 |
| 95% | 205 lb | 2 |
| 93% | 200.7 lb | 3 |
| 90% | 194.3 lb | 4 |
| 87% | 187.8 lb | 5 |
| 85% | 183.5 lb | 6 |
| 83% | 179.1 lb | 7 |
| 80% | 172.7 lb | 8 |
| 77% | 166.2 lb | 9 |
| 75% | 161.9 lb | 10 |
| 70% | 151.1 lb | 12 |
| 67% | 144.6 lb | 15 |
| 65% | 140.3 lb | 16 |
| 60% | 129.5 lb | 20 |
| 55% | 118.7 lb | 24 |
| 50% | 107.9 lb | 30 |
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How the one rep max calculator works
Your one rep max (1RM) is the most weight you can lift once with good form. Rather than testing it, you can predict it from a set of several reps. Epley (1985): 1RM = weight × (1 + reps / 30). Brzycki (1993): 1RM = weight × 36 / (37 - reps).
The formulas agree closely for 2 to 10 reps and drift apart for higher reps. The training table shows the weight for each percentage of your 1RM and the reps most people can do at it.
Using and checking your result
Published by JustYourCalculator. Check the units and assumptions above, and compare a known example before relying on the output. Calculations use browser arithmetic and may round displayed values.
This tool provides an estimate, not a diagnosis, treatment plan or individualized medical advice. Population formulas may not fit children, pregnancy, athletes or people with health conditions. Discuss health decisions with a qualified clinician.
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