One Rep Max (1RM) Calculator

Calculator Tools

Estimate your max lift and training weights

FreePrivateInstant
Weight lifted (kg or lb)
Reps completed
Full guide, 3 min readOne rep max: estimate your max lift without risking itRead the story behind this tool →
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History

All history →

One Rep Max (1RM) Calculator — at a glance

Find your estimated max lift without testing it.

You enter
80 kg × 6 reps
Calculate 1RM
Result
Estimated 1RM

How to use it — step by step

The weight you lifted and how many reps you did (up to 12 is most accurate).

1

Enter your values

Fill in the fields. Default numbers are shown so you can see how it works.

2

Press Calculate 1RM

The answer appears at once as large result cards.

3

Copy or share

Copy the result, or share a link that opens with your numbers filled in.

Pro tips

Small things that make the result better.

✦Results are most accurate for 10 reps or fewer.
✦Use a spotter when you test heavy lifts.
✦Percent rows help plan sets.

Quick facts

Freeno signup
Privateruns in your browser
Instantresult in a second
No limituse it as often as you like

Frequently Asked Questions

Which formula is best?+

They give close results at low reps. The average of three is shown first.

Is it safe to test my max?+

Only with good form and a spotter. The estimate lets you avoid maxing out.

Is my data safe?+

Yes. Everything runs inside your own browser. Your text, files and images are never uploaded to any server.

Is this tool really free?+

Yes — completely free, no signup, no watermark and no usage limit.

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