One Rep Max Calculator
Estimate your one-rep max for any lift using the Epley formula.
How to Use This Calculator
- Enter your details in the fields above — all fields are used only in your browser, nothing is stored or sent anywhere.
- Double-check your units (cm/kg) before submitting for the most accurate result.
- Click Calculate to see your personalized result instantly.
- Results are estimates based on established formulas — for medical decisions, always confirm with a healthcare professional.
Frequently Asked Questions
How accurate is a 1RM estimate?
Formulas like Epley are typically accurate within 5-10% for rep ranges under 10 — for exact numbers, a supervised max-effort test is more precise.