Enter your details
Your inputs stay in this browser. Results are informational estimates, not medical, dietary, or training prescriptions.
How to use the One Rep Max Calculator
Enter the requested values and review the calculation as a planning estimate.
Enter your details
Enter a load, select kilograms or pounds and enter repetitions completed with good form.
Review the calculation
Compare the Epley, Brzycki and Lombardi estimates.
Interpret with context
Do not treat an estimate as a requirement to attempt a maximal lift.
Frequently Asked Questions
What is a one-repetition maximum?
This calculator provides an informational estimate based on the values and method you select.
How does the calculator estimate a one-rep max?
The result uses the displayed calculation method and updates when you change the inputs.
Why are several one-rep-max estimates shown?
Individual circumstances and measurement differences can affect how the estimate should be interpreted.
What repetition range is most reliable?
Use the result as a planning reference rather than a diagnosis, prescription, or guarantee.
Can I use kilograms or pounds?
Choose the unit that matches your measurement wherever a unit selector is available.
Should I test a true one-rep max?
For the most useful comparison, enter recent measurements and use consistent input units.
Does this replace coaching or medical guidance?
Seek advice from an appropriately qualified professional for personal medical, nutrition, or training decisions.