One Rep Max Calculator
Estimate your 1RM from any set, with training percentages for programming.
Training Percentages
| % of 1RM | Weight | Typical Use |
|---|---|---|
| 95% | 201 lb | strength (1–3 reps) |
| 90% | 191 lb | strength (1–3 reps) |
| 85% | 180 lb | strength (3–6 reps) |
| 80% | 170 lb | strength (3–6 reps) |
| 75% | 159 lb | hypertrophy (6–12 reps) |
| 70% | 148 lb | hypertrophy (6–12 reps) |
| 65% | 138 lb | endurance (12+ reps) |
| 60% | 127 lb | endurance (12+ reps) |
DISCLAIMER: 1RM estimates get less accurate above ~10 reps. Always test true maxes with a spotter and proper warm-up. Not medical advice.
What Is the One Rep Max Calculator?
The One Rep Max Calculator is a free online tool that lets you estimate your 1RM from any set, with training percentages for programming. It runs entirely in your browser — your text and files never leave your device, so it's fast and private. There's nothing to install and no sign-up required.
How It Works
Using the One Rep Max Calculator takes seconds. Paste or type your content into the input area (or upload a file where supported), adjust any options to fit your needs, and the result updates instantly. You can then copy the output to your clipboard, download it, or clear everything and start again. Because all processing happens locally with JavaScript, it works offline once the page has loaded.
When to Use It
Reach for the One Rep Max Calculator whenever you need a quick, reliable way to estimate your 1RM from any set, with training percentages for programming. It's popular with writers, students, developers, marketers and anyone who works with calculators day to day. Bookmark it alongside the other Calculators in our toolbox so it's always one click away.
Frequently Asked Questions
- Is the One Rep Max Calculator free to use?
- Yes. Every tool on the site is completely free, with no account, login or download required.
- Is my data private?
- Absolutely. The One Rep Max Calculator processes everything locally in your browser. Your text and files are never uploaded to a server, so your data stays on your device.
- Does it work on mobile?
- Yes. The One Rep Max Calculator is fully responsive and works on phones, tablets and desktops in any modern browser.
- Do I need to install anything?
- No installation is needed — it runs in the browser. We also offer an optional browser extension and mobile app for quick access to popular conversions.
Last reviewed: 2026-06-27