One Rep Max Calculator

Enter a weight and how many reps you did to estimate your one-rep max, with a breakdown of training percentages for your program.

Weight lifted Reps Unit

📖 New to this? Read How to Calculate Your One-Rep Max (1RM).

How to use the One Rep Max Calculator

Enter the weight and reps you lifted.
Click Calculate 1RM.
Use the percentage table for training.

100% free, no sign-up, and it all runs in your browser — your data never leaves your device.

FAQ

How is 1RM estimated?

It averages two trusted formulas (Epley and Brzycki). Estimates are most accurate at 10 reps or fewer.

Add this tool to your website — free

Paste this where you want the tool to appear. It links back to ToolKraken.

Option 1 — iframe

<iframe src="https://www.toolkraken.com/embed/one-rep-max-calculator" width="100%" height="520" style="border:1px solid #e5e7eb;border-radius:12px" loading="lazy" title="One Rep Max Calculator"></iframe>

Option 2 — script

<script src="https://www.toolkraken.com/embed.js" data-tool="one-rep-max-calculator"></script>

One Rep Max Calculator

How to use the One Rep Max Calculator

FAQ

How is 1RM estimated?

Add this tool to your website — free

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