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One rep max calculator
Your estimated one rep max from any set, plus your rep maxes and training weights.
1 to 12
Estimated one rep max from 100 kg × 5 reps
Your rep maxes
The most you could lift for each number of reps, rounded to the nearest plate jump (2.5 kg or 5 lb).
| Reps | Weight | % of 1RM |
|---|---|---|
| 1 rep | 115 kg | 100% |
| 2 reps | 110 kg | 95% |
| 3 reps | 105 kg | 93% |
| 4 reps | 102.5 kg | 90% |
| 5 reps | 100 kg | 87% |
| 6 reps | 97.5 kg | 85% |
| 8 reps | 92.5 kg | 80% |
| 10 reps | 85 kg | 75% |
| 12 reps | 80 kg | 70% |
Training percentages
Programs often prescribe weights as a percentage of your one rep max. Here are yours.
| % of 1RM | Weight | Typical use |
|---|---|---|
| 95% | 110 kg | Heavy singles and doubles |
| 90% | 102.5 kg | Heavy triples |
| 85% | 97.5 kg | Sets of 5 |
| 80% | 92.5 kg | Sets of 6 to 8 |
| 75% | 85 kg | Sets of 8 to 10 |
| 70% | 80 kg | Sets of 10 to 12 |
| 65% | 75 kg | Volume and technique |
| 60% | 70 kg | Warm-up and speed work |
How the estimate works
The calculator averages two of the most widely used formulas:
- Epley: 1RM = weight × (1 + reps ÷ 30)
- Brzycki: 1RM = weight × 36 ÷ (37 − reps)
Both are close at around 10 reps or fewer and drift apart at higher reps, which is why the estimate is most reliable from a heavy set of 3 to 8. It's an estimate: your true max depends on technique, fatigue and how close to failure the set was.
Should you test your 1RM?
You don't have to. Estimating from a heavy set of 3 to 5 is safer, needs no spotter and is accurate enough to set training weights. If you do test, warm up in steps (around 50%, 70%, 85% and 92% of your expected max), rest three to five minutes between attempts, and use safety bars or a spotter.
Get your 1RM from every set you log
Elevus estimates your one rep max from every set you log, charts it over time for every exercise, and suggests the weight and reps for your next session.
Download on theApp StoreFAQ
How do you calculate your one rep max?
Lift a weight for as many good reps as you can (ideally 3 to 8), then use a formula such as Epley: weight × (1 + reps ÷ 30). For example, 100 kg for 5 reps gives about 117 kg by the Epley formula; this calculator averages Epley and Brzycki for about 115 kg.
How accurate is a 1RM calculator?
Usually within a few percent when the set is 10 reps or fewer and taken close to failure. Accuracy drops at higher reps, and varies between exercises and people.
What percentage of my 1RM should I train at?
Roughly 80 to 90% for strength (sets of 3 to 6), 65 to 80% for muscle growth (sets of 6 to 12), and below 65% for warm-ups and technique work.
Does this work for squat, bench press and deadlift?
Yes. The formulas work for any barbell or machine lift. They're less reliable for bodyweight exercises and very high-rep sets.
References
- Epley B. Poundage chart. Boyd Epley Workout. Lincoln, NE; 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.