One-rep max calculator

The most you could lift once, estimated from a set of 1 to 10 reps, and the weight to use for each rep count.

Your estimated one-rep max

219 lb

from 8 reps with 175 lb

Epley 222 lb
Brzycki 217 lb
NSCA chart 219 lb

If you lifted 175 lb for 8 reps, your one-rep max is about 219 lb, the average of the Epley (222 lb) and Brzycki (217 lb) formulas.

The NSCA’s training load chart gives 219 lb, since it puts 8 reps at about 80% of a max.

I’m not a doctor or a dietitian. This is an estimate, for information only. For decisions about your health, check with a professional.

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Weights for each rep count (NSCA chart)
Reps	% of max	Weight
1	100%	219 lb
2	95%	209 lb
3	93%	204 lb
4	90%	198 lb
5	87%	191 lb
6	85%	187 lb
7	83%	182 lb
8 (your set)	80%	176 lb
9	77%	169 lb
10	75%	165 lb
12	70%	154 lb

How it works

Epley: max = weight × (1 + reps ÷ 30).
Brzycki: max = weight ÷ (1.0278 − 0.0278 × reps).
The calculator shows the average of the two; with 1 rep, your max is the weight itself. Then it uses the NSCA’s training load chart to turn your max into a weight for each rep count: 5 reps at about 87% of it, 8 at 80%, 10 at 75%.

Worked example

175 lb for 8 reps. Epley: 175 × (1 + 8 ÷ 30) = 221.67 lb. Brzycki: 175 ÷ (1.0278 − 0.0278 × 8) = 175 ÷ 0.8054 = 217.28 lb. Average: 219.47, so about 219 lb. The NSCA chart puts 8 reps at 80% of a max: 175 ÷ 0.80 = 218.75, again about 219 lb. For sets of 5, 87% of 219.47 is about 191 lb.

Sources

Text checked on September 30, 2026

Good to know

It’s an estimate. The formulas and the chart come from coaching practice more than from lab studies, and how many reps you can do at a given weight varies from person to person and from lift to lift.
The fewer the reps, the better the estimate: in one study, sets of 5 predicted the max best, and the authors advise no more than 10 reps for this kind of estimate. That’s why the calculator stops at 10.
Endurance athletes can often do more reps at a given percentage than the chart assumes, so their estimate may come out high. In one study, runners did about 20 reps at 80% of their max on the leg press; weightlifters did about 12.
Round the weights in the table to what your plates allow.

Frequently asked questions

What is a one-rep max?

The heaviest weight you can lift once, with good form, in a given exercise. Many training programs set their weights as a percentage of it.

Which formula is more accurate, Epley or Brzycki?

They agree closely: within about 4% of each other at every rep count from 1 to 10, and almost the same at 10 reps. Neither is exact for everyone, so the calculator averages them and checks the result against the NSCA chart.

How do I use the percentage table?

Pick the number of reps you want to train with and use the weight next to it. With a 219 lb max, sets of 5 are about 191 lb (87%). The NSCA’s own example: with a 200 lb max, you should be able to do 10 reps at 150 lb (75%).

Is it safe to test my real max?

It’s your heaviest possible lift, so that’s when the risk is highest. The NSCA counts lifts like the bench press and the back squat among those that need a spotter. Estimating from a set of 3 to 10 reps skips the heaviest single.

Why can’t I enter more than 10 reps?

Because the estimate gets less reliable as the reps go up. In one study, sets of 5 predicted the max best, and the authors advise using no more than 10 reps.