PushBeyond
Free tool

One-rep max calculator

Enter the weight you lifted and how many clean reps you managed. The calculator estimates your one-rep max (1RM), the heaviest weight you could lift once, and turns it into training weights from 60 to 100 percent. It is most accurate from a hard set of 1 to 5 reps.

Reps completed
5

Estimated 1RM

93.3 kg

Epley 93.3 kg · Brzycki 90 kg

Training weights from your 1RM

% of 1RMWeightAbout reps
100%93.5 kg1
95%88.5 kg2
90%84 kg3
85%79.5 kg5
80%74.5 kg8
75%70 kg10
70%65.5 kg13
65%60.5 kg16
60%56 kg20

Weights rounded to 0.5 kg. Rep counts are approximate and come from the same formula.

Put this calculator on your website

Free for any site: paste the code where the calculator should appear. It updates itself, sets no cookies and loads nothing from anyone else. The line under it credits PushBeyond.

<iframe src="https://push-beyond.com/embed/en/one-rep-max-calculator" title="1RM calculator" loading="lazy" style="width:100%;max-width:640px;height:1060px;border:0;border-radius:12px"></iframe>
<p style="max-width:640px;font-size:13px">1RM calculator by <a href="https://push-beyond.com/tools/one-rep-max-calculator">PushBeyond</a></p>
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How to get a number worth using

The formula can only be as good as the set you give it. An easy set of five says nothing about your limit.

  • Use a set taken close to failure, where one more rep would have been doubtful.
  • Pick a compound lift such as the squat, bench press, deadlift or overhead press.
  • Keep it to 10 reps or fewer, ideally 1 to 5.
  • Count only reps with full range of motion and your usual technique.

Using the percentage table

Many programmes prescribe work as a percentage of your 1RM: three sets of five at 80 percent, for instance. The table does that conversion from your estimate, so you never need to spend a session testing a true maximum.

The rep column is roughly how many reps that load allows, worked backwards from the same formula. Treat it as a ceiling rather than a target: most working sets should stop a rep or two short of it.

Why two formulas

Epley and Brzycki were fitted to different groups of lifters. Below 10 reps Epley reads a few percent higher, at exactly 10 they agree, and above 10 Brzycki climbs faster and the two drift apart quickly. The PushBeyond app uses Epley for the estimates in your exercise history, so that is the headline figure here too.

Whichever you use, stay with it. The trend over weeks and months tells you far more than which formula sits closer to the truth on one day.

FAQ

Frequently asked questions

How accurate is a 1RM calculator?

Within a few percent for most people on a hard set of 1 to 5 reps, less so beyond 10. Muscle make-up and experience with heavy singles differ, so two people with the same 5-rep set can have different true maxima.

Is it safe to test my real 1RM?

It can be, with a spotter or safety bars, a thorough warm-up and solid technique. For most people it is unnecessary: the estimate carries the same information without the fatigue or risk of a maximal attempt.

Does it work in pounds?

Yes. The formulas work in any unit, so a weight entered in pounds gives a result in pounds. The labels say kg because that is what gyms in Belgium and most of Europe use.

Can the app work this out for me?

Yes. PushBeyond estimates your 1RM from the sets you log and charts it per exercise, so you can follow it over time without doing the maths.

Track your 1RM without the maths

PushBeyond estimates your one-rep max from every set you log and charts it over time. Free on iPhone and Android.

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