🏋️ One-Rep Max Calculator

What is One-Rep Max Calculator?

The One-Rep Max Calculator estimates the heaviest weight you can lift for a single rep from any set you have already completed. Enter the weight and reps of a hard set and the tool applies the Epley and Brzycki formulas to estimate your 1RM, then builds a training-percentage table from 50 to 100 percent with suggested rep ranges. Switch between kilograms and pounds and pick the estimate that matches how you train. Everything is computed instantly in your browser with no account needed.

How to Use One-Rep Max Calculator

1. Enter the weight you lifted and how many reps you completed
2. Choose your unit and the estimate formula you prefer
3. Read your 1RM and scan the percentage table for working-set loads

Why Use Our One-Rep Max Calculator?

• Epley, Brzycki and averaged one-rep-max estimates in one place
• A full 50–100 percent training table with target rep ranges
• Kilogram and pound switching without re-entering data
• No account, no uploads — calculations happen locally

Common Use Cases

• Planning strength blocks around realistic working-set percentages
• Comparing a recent set to your estimated lifetime max
• Estimating a safe start weight before testing a true one-rep max

Frequently Asked Questions

• How accurate is an estimated one-rep max?▾
  Epley and Brzycki formulas are well-validated for sets of up to about ten reps and give a useful training estimate. They are not a substitute for a real tested 1RM.
• Which formula should I use?▾
  Epley is the most common default. The Average option blends Epley and Brzycki and is a good middle ground for newer lifters.
• Why does the table show rep counts per percentage?▾
  The percentages map to common training loads — 85 percent of 1RM is roughly a five-rep working weight — so you can plan sets straight from the table.