RepMaxLab is a small, independent website with free calculators for people who lift weights. There is no account to create, no app to install and no paywall. Open a page, type in a set and get your numbers.
What you will find here
- One Rep Max Calculator
- Bench Press Max Calculator
- Squat Max Calculator
- Deadlift Max Calculator
- RPE Calculator
- One Rep Max Percentage Calculator
- One Rep Max Chart
How the calculators work
Every result comes from published formulas, and each page shows the equations it uses so you can check the math yourself. The calculations run in your own browser. The weights and reps you type are not sent to us or stored on a server.
Before launch we tested the calculators against worked examples. For instance, 225 lb for 10 reps returns 300 lb with both the Epley and Brzycki formulas, and 100 kg for 5 reps returns 116.7 kg with Epley.
What RepMaxLab is not
We are not doctors, physical therapists or your coach. The calculators give estimates for general fitness use. They can't account for your health, your injury history or how you feel on a given day. Please read the disclaimer before you load a bar based on any number from this site.
How the site is paid for
RepMaxLab is free to use. To cover its costs, the site may show ads through Google AdSense. Ads never change what a calculator tells you. The privacy policy explains how advertising cookies work and how to opt out.
Get in touch
Found a mistake, or want a calculator we don't have yet? Email contact@repmaxlab.com or visit the contact page.