One-Rep Max (1RM) Calculator
Find your estimated one-rep max in seconds and know how much to lift in every intensity range of your training.
What 1RM is and why it matters
1RM (one-rep max) is the heaviest weight you can lift in an exercise for a single repetition, with full and safe execution.
Training from percentages of your 1RM is how strength coaches most often set the intensity of each set, without testing your true maximum load at every session.
This calculator estimates your 1RM from a submaximal test — a load you have already lifted for a few repetitions. Avoid testing your true maximum load without the supervision of a professional.
Questions about the calculator
Is the 1RM calculator accurate?
The Epley formula used here is a validated and widely used estimate, but the real value can vary from person to person — especially with more than 10 repetitions in the test.
How many repetitions should I use in the test?
A number between 1 and 10 repetitions is ideal: the more repetitions, the less accurate the estimate becomes.
How do I use the percentage table?
Each row shows the approximate weight for that percentage of your 1RM — useful to plan sets for strength (above 85%), hypertrophy (65% to 80%) or endurance (below 65%).
Can I track my load progress in Streak?
Yes — log your workouts in Streak and watch your load grow over time in your progress gallery.
Ready to train with a target?
Log your loads in Streak and follow your progress workout after workout.
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