Free Ring Sizer was created to solve the most frustrating part of buying jewelry online: finding your exact ring size without guesswork or apps.
Screens vary drastically in pixel density (DPI/PPI) across laptops, tablets, and smartphones. Free Ring Sizer utilizes standard reference calibration — using ISO credit cards (85.60 mm), common currency coins, or physical rulers — to achieve true 1:1 millimeter precision on any display.
All measurements and sizing calculations execute 100% locally in your browser.
Zero personal data tracking, zero accounts, and zero photo uploads needed.