One rep max calculator
Enter a set you’ve done. Get your estimated max, the weight for every rep range, and exactly which plates go on the bar.
Estimated one rep max, bench press
260lb
See all 7 formulas
- Epley262.5
- Brzycki253.1
- Lombardi264.3
- Mayhew267.8
- O’Conner253.1
- Wathan262.3
- Lander255.8
Your training weights
Tap a row to load it on the bar.
| % of 1RM | Weight | Reps | Best for |
|---|---|---|---|
| 260 | 1 | Max test | |
| 245 | 2 | Peak strength | |
| 235 | 3–4 | Strength | |
| 220 | 5–6 | Strength | |
| 210 | 7–8 | Strength and size | |
| 195 | 9–10 | Muscle growth | |
| 180 | 11–12 | Muscle growth | |
| 170 | 13–15 | Muscle growth | |
| 155 | 16–20 | Endurance, technique | |
| 145 | 20–24 | Warm-up, endurance | |
| 130 | 25+ | Warm-up |
Your rep maxes
The most weight you could likely lift for each number of reps.
| Reps | Weight |
|---|---|
| 1 rep | 260 |
| 2 reps | 250 |
| 3 reps | 240 |
| 4 reps | 235 |
| 5 reps | 225 |
| 6 reps | 220 |
| 7 reps | 215 |
| 8 reps | 205 |
| 9 reps | 200 |
| 10 reps | 195 |
| 11 reps | 190 |
| 12 reps | 185 |
How the calculator works
Your one rep max (1RM) is the heaviest weight you can lift for a single clean rep. Testing it directly is tiring and risky, so coaches estimate it from a heavier set of a few reps. Enter the weight and the reps you managed, and the calculator runs seven published formulas (Epley, Brzycki, Lombardi, Mayhew, O’Conner, Wathan and Lander) and averages them.
From that estimate it works backwards: the training weight for every percentage from 50 to 100%, the most you could likely lift for 1 to 12 reps, and the plates to load on each side of a standard bar. Weights are rounded to what you can actually load, 5 lb or 2.5 kg jumps.
How to get the most accurate number
- Use a heavy set. Sets of 2 to 6 reps give the closest estimates. Above 10 reps the formulas start to disagree.
- Go close to failure. The maths assumes you couldn’t have done another rep. If you stopped with 3 left in the tank, your real max is higher.
- Use clean reps only. Count reps with full range of motion and no bounce. A half-depth squat inflates the number.
- Re-check every 4 to 6 weeks. Your max moves as you train, so your working weights should too.
Using your 1RM in a program
Most strength programs prescribe weights as a percentage of your max. A common split: 80 to 90% for 3 to 6 reps on strength days, 65 to 80% for 8 to 12 reps on muscle-building days, and lighter sets for warm-ups and technique. If you want a routine built around your goal and equipment, try the free workout generator, or read the guide to picking a workout split.
Frequently asked questions
How accurate is a one rep max calculator?
Within about 5% for most people when you enter a set of 2 to 6 reps taken close to failure. Accuracy drops as reps go up: a 12-rep set gives a rougher estimate than a 3-rep set, because endurance starts to matter more than strength. Treat the number as a planning tool, not a promise.
Which 1RM formula is the best?
No single formula wins for every lift and every person. Epley and Brzycki are the most widely used and agree closely between 2 and 10 reps. This calculator shows seven published formulas and uses their average, which smooths out each one's bias.
Should I test my real one rep max?
You don't need to. Most training programs only need an estimate, and a true max attempt carries more injury risk, needs a spotter for bench and squat, and costs recovery. If you do test, warm up in 4 to 5 progressively heavier singles and stop when bar speed slows sharply.
What percentage of my 1RM should I train at?
Roughly 80 to 90% for 3 to 6 reps to build strength, 65 to 80% for 8 to 12 reps to build muscle, and below 65% for endurance or technique work. The percentage chart above turns your number into those working weights.
Does this work in kilograms?
Yes. Switch to kg and the calculator rounds working weights to 2.5 kg jumps and loads a 20 kg bar with standard kilo plates.