# One Rep Max Calculator

> One rep max calculator: estimate your 1RM from weight lifted and reps using Epley, Brzycki, and Lombardi formulas with training charts. Free, no signup.

- **Canonical URL:** https://boringtoolskit.com/one-rep-max-calculator/
- **Category:** Everyday Calculators
- **Evidence level:** authored-methodology
- **Reviewed:** August 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

## How it works

1RM = weight × (1 + reps ÷ 30) (Epley formula).

## Sources

- [Calculation methodology and verification standard](/methodology/)

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