One rep max calculator
Enter a weight you lifted and how many reps you got. See your estimated one rep max and the weight for common training percentages.
| % of 1RM | Weight |
|---|
Estimate only. Lift within your limits and use a spotter for heavy attempts.
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Questions
What is a one rep max?
Your one rep max, or 1RM, is the heaviest weight you can lift once with good form on a given exercise.
How is 1RM estimated?
The Epley formula is weight times (1 plus reps divided by 30). The Brzycki formula is weight times 36 divided by (37 minus reps). This calculator shows both and their average.
How accurate is it?
Estimates are most reliable from sets of about 2 to 10 reps. Results use the same unit you enter, pounds or kilograms. Use a spotter and good judgement before attempting heavy singles.
Is my data saved or sent anywhere?
No. The calculation runs in your browser and nothing you type is sent to a server.