1RM calculator — one rep max
Enter the weight and reps from a working set — the calculator estimates what you could lift once, lays out training weights by percentage and shows your level relative to bodyweight. It works for the bench press, squat, deadlift and any other lift.
Epley formula — the same one the log uses
Training weights from your 1RM
| % of 1RM | Weight | Reps | Used for |
|---|---|---|---|
| 100% | 215 lb | 1 | testing a max |
| 95% | 205 lb | 2 | testing a max |
| 90% | 195 lb | 3 | strength |
| 85% | 185 lb | 5 | strength |
| 80% | 175 lb | 8 | strength |
| 75% | 160 lb | 10 | muscle growth |
| 70% | 150 lb | 13 | muscle growth |
| 65% | 140 lb | 16 | muscle growth |
| 60% | 130 lb | 20 | volume and technique |
| 55% | 120 lb | 25 | volume and technique |
| 50% | 110 lb | 30 | volume and technique |
Your level relative to bodyweight
| Level | Bench press | Squat | Deadlift |
|---|---|---|---|
| Beginner | 90 ×0.5 | 135 ×0.8 | 180 ×1 |
| Novice | 135 ×0.8 | 225 ×1.3 | 270 ×1.5 |
| Intermediate | 225 ×1.3 | 270 ×1.5 | 360 ×2 |
| Advanced | 315 ×1.8 | 405 ×2.3 | 450 ×2.5 |
| Elite | 360 ×2 | 495 ×2.8 | 540 ×3 |
These are rough guides for recreational lifters — 1RM to bodyweight ratios pulled together from public tables. They are not federation standards, which come with their own weight classes, rules and equipment.
How the 1RM is calculated
Your 1RM is the weight you could lift exactly once with good form. You don’t need to test it under the bar, and it’s safer not to: a set of 3–10 reps estimates it well.
The main formula here is Epley: 1RM = weight × (1 + reps / 30). The GymAssist log uses the same one for your estimated max and records. Brzycki and Lombardi agree with it at low reps and drift apart at higher reps, which is why the average is shown too.
The closer the set was to failure, the better the estimate. If you had three or four reps left in the tank, your real max is higher than the number above.
How to use the chart
Strength work usually sits at 80–90% of 1RM for 2–6 reps, muscle-building work at 65–80% for 6–12 reps. The chart rounds weights to the nearest plate step: 2.5 kg or 5 lb.
The rep counts in the chart run the same Epley formula backwards. Treat them as a guide: at the same percentage most people get more reps on squats and deadlifts than on the bench.
FAQ
How many reps should I enter?
A set of 3–8 reps taken close to failure works best. At 1–2 reps the error is tiny, but such a set is already almost a max; past 10 reps the formulas start to disagree.
Does it work for dumbbells and machines?
Yes — the formula works for any lift with a weight and reps. For dumbbells, enter the weight of one dumbbell and the result will be per hand.
How is a 1RM different from strength standards?
Your 1RM is your personal max. Federation standards are set for competitions, with weight classes and equipment rules. The levels on this page are everyday guides for recreational lifters.
How often should I recalculate my 1RM?
Every three or four weeks, or whenever your working weights have clearly gone up. In the GymAssist log you don’t have to: the estimated max updates after every set you log.
The log calculates your 1RM for you
Log a set and GymAssist updates your estimated max and personal record for every exercise, tells you when to add weight and shows the load on a map of 40 muscles.
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