Health

One-Rep Max Calculator

1RM calculator using Epley, Brzycki, or Lombardi estimates with common training-load percentages.

Estimate a one-repetition maximum (1RM) from weight and repetitions using a standard formula. Formulas become less reliable with high-repetition sets and vary by exercise and lifter.

Do not attempt a true maximal lift without appropriate experience, equipment, setup, and supervision. Stop for pain, dizziness, or unusual symptoms.

Frequently asked questions

Which formula is most accurate?

No formula is best for every exercise and person. Use one method consistently and compare it with training experience.

Should I use a 15- or 20-rep set?

Higher-repetition sets generally produce less reliable 1RM estimates.

Does the tool know pounds or kilograms?

The output uses the same weight unit entered.