OhMyCalc

One Rep Max Calculator

Calculate your one-repetition maximum (1RM) using Brzycki and Epley formulas. Get training weight percentages.

How to Use the One Rep Max Calculator

  1. Enter the weight you lifted in kilograms.
  2. Enter the number of repetitions you completed with that weight.
  3. Click Calculate to see your estimated one-rep max via the Brzycki and Epley formulas.
  4. Use the training weight table to plan sets at 50–90% of your 1RM.

Quick Reference

FromTo
Height (adult M)170–180 cm
Height (adult F)160–170 cm
Weight (adult M)65–85 kg
Weight (adult F)55–70 kg
Resting heart rate60–100 bpm
Normal BP120/80 mmHg

Use Cases

Formula

Brzycki: 1RM = weight / (1.0278 − 0.0278 × reps). Epley: 1RM = weight × (1 + reps/30).

Frequently Asked Questions

How to use?
Enter the weight you lifted and the number of reps completed, then click Calculate to estimate your one-rep max.
Calculation accuracy?
Calculations are performed with high precision.
Is it free?
Yes, all calculators are completely free.