1RM calculator: your one-rep max from weight and reps
Enter a weight and how many reps you lifted it for — the calculator estimates your one-rep max with three formulas and shows training weights from 50 to 100%. Works for bench press, squat, deadlift and other barbell lifts. No need to actually max out.
Your set
Your 1RM
Enter weight and reps — the result appears right away.
Training weights
| % of 1RM | Weight, kg | Reps | Plates |
|---|---|---|---|
| 100% | — | 1 | |
| 95% | — | 2 | |
| 90% | — | 3–4 | |
| 85% | — | 5–6 | |
| 80% | — | 7–8 | |
| 75% | — | 9–10 | |
| 70% | — | 11–12 | |
| 65% | — | 13–15 | |
| 60% | — | 16–20 | |
| 55% | — | 20+ | |
| 50% | — | 20+ |
Log the result in your diary
Save the set in your workout diary: weight history and a progress chart for each exercise show how your max grows.
What is 1RM
1RM, or one-rep max, is the heaviest weight you can lift once in an exercise with proper form. Most strength programs prescribe intensity as a share of it: “5×5 at 80%” means five sets of five reps with 80% of your 1RM.
Testing a true max is hard and risky: it takes a long warm-up, a spotter and experience. That is why 1RM is usually estimated from a multi-rep set — the more reps you did with a weight, the further it is from your max. Beginners should not max out at all: in the first months strength grows anyway, and an estimate is enough for planning.
How to use the calculator
- Take a recent set from your workouts: the weight and the number of reps done with clean form — no cheating and no help from a spotter.
- Sets of 2–8 reps give the most accurate estimate. Up to 12 reps the result is still reliable; beyond that the error grows.
- Enter the weight (decimals are fine, e.g. 82.5) and the reps — the result and the chart update instantly.
- Go by the average. The spread between formulas shows how rough the estimate is.
Count the bar itself: a standard Olympic bar weighs 20 kg, a women's bar 15 kg.
How to use the percentage chart in training
The chart turns your 1RM into training weights. Next to each percentage is the typical number of reps to failure with that weight. In regular training you stop short of failure and keep 1–3 reps in reserve, so do fewer reps than listed.
- 85–95% — strength: 1–5 reps, 3–6 sets, 3–5 minutes rest. Only with solid technique and a spotter.
- 70–85% — muscle and strength: 6–12 reps, 3–4 sets, 1.5–3 minutes rest. The main working zone of most programs.
- 50–70% — technique, volume and warm-up: 12–20 reps. Warm-up sets before working sets start here.
Recalculate your 1RM every 4–6 weeks from a fresh set: as your weights go up, so does your max, and the whole chart moves up with it.
1RM formulas
The calculator uses three common formulas and shows their average. w is the weight lifted, r is the number of reps.
- Epley
1RM = w × (1 + r / 30)The most popular formula, works well for 3–10 reps.
- Brzycki
1RM = w × 36 / (37 − r)Accurate for low reps, starts to overestimate past 10 reps.
- Lombardi
1RM = w × r^0.1Gives the most conservative estimate for high reps.
With a single rep every formula returns the weight itself. Results are rounded to 0.5 kg. This is an estimate: your real max depends on experience, the exercise and how you feel that day, and can differ by 5–10%.
Technique for the main lifts
A 1RM estimate only makes sense with good form. Before heavy sets, check how to perform the exercise:
FAQ
How do I calculate my bench press 1RM?
After warming up, do a set of 3–8 bench press reps with proper form and enter the weight (bar included) and the reps into the calculator. For example, 80 kg for 6 reps gives a one-rep max of about 95 kg.
How accurate is a one-rep max estimate?
For sets of up to 10 reps the estimate is usually within a few percent of your real max. Past 12 reps the error grows: high-rep work depends more on endurance than on strength, so the calculator shows a warning.
Do I need to test my 1RM for real?
No — the estimate is enough to plan your training. If you do test it, only after a thorough warm-up, with a spotter or safety pins in the rack, and no more than once every few months. Beginners in their first months of training should not max out.
Which formula is the most accurate?
There is no single best one: each was derived from its own group of lifters and exercises. That is why the average is the best guide — it smooths out the bias of each formula. If one of them turns out to match your real max over time, use that one.
Does the calculator work for squats and deadlifts?
Yes, for any free-weight exercise where the load is easy to measure: squat, deadlift, overhead press, bent-over row. For bodyweight exercises such as pull-ups you have to account for body weight, so the estimate is less accurate.
How often should I recalculate my 1RM?
Every 4–6 weeks or when you switch programs. The easiest way is to log your sets in a workout diary: your weight and rep history shows whether you are getting stronger, and you always have a recent set to calculate from.
Other calculators
- Barbell plate calculator
Which plates to load on each side of the bar for a target weight, plus warm-up sets with plate breakdown.
- RPE and RIR calculator
Working weight for a target rep count at a given RPE and estimated 1RM from a set — full RPE chart.
- Wilks, DOTS and IPF GL calculator
Bodyweight-adjusted strength points: Wilks (classic and 2020), DOTS and IPF GL for powerlifting total and bench.
- Powerlifting standards
Strength level from Beginner to Elite and Russian EVSK 2026 rank for the bench and total — and how far the next one is.
- Bench press standards
Russian EVSK classic bench ranks and strength levels by bodyweight for men and women.
- Squat standards
Squat strength levels by bodyweight for men and women, with a level calculator.
- Deadlift standards
Deadlift strength levels by bodyweight for men and women, with a level calculator.