About True Ring Size
We built True Ring Size because getting the wrong ring size is one of the most avoidable — and frustrating — mistakes in jewelry buying. Our mission is simple: give everyone access to an accurate, free ring sizing tool that works on any device, anywhere in the world.
Our Mission
73% of people who guess their ring size get it wrong. That number is startling — and completely preventable. True Ring Size exists to make that guesswork obsolete.
We provide a free, calibrated, in-browser ring sizer that works on desktops, tablets, and mobile phones. No downloads, no accounts, no payments — ever. Place your ring on screen, resize the circle, and get your exact size in every international format instantly.
Why We Built This
The story starts where most ring-buying disasters start: a surprise proposal. The ring was beautiful. The size was wrong. Two weeks of back-and-forth with the jeweler later, the moment had passed, but the lesson stayed.
We looked at what was available online — plastic ring sizer kits that ship in 5 days, printable PDFs that measure incorrectly on most printers, and paid apps that require downloading. None of them were instant, free, and accurate. So we built one that is.
True Ring Size uses your device's actual pixel density — calibrated against a reference object you already own (a credit card or a known ring) — to measure with sub-millimeter accuracy. We've validated the tool against physical ring mandrels across 100+ device models.
How the Tool Works
01
Calibrate Your Screen
Select your device from our list of 100+ models, or place a credit card on screen for pixel-perfect calibration. Takes under 5 seconds.
02
Place Your Ring or String
Already have a ring? Set it on the circle and match the inner edge. No ring? Wrap a string around your finger and enter the length.
03
Get Every Size Instantly
Your results appear in US, UK, EU, Indian, and Japanese formats simultaneously — no extra steps, no conversion needed.
What We Stand For
Free, forever
Ring sizing should be free. We keep the lights on through non-intrusive advertising. No paywalls, no subscriptions, no upsells.
Privacy by design
We don't collect personal data. Calibration settings are stored only in your browser's localStorage and never leave your device. See our Privacy Policy.
Accuracy over everything
Every device calibration profile is verified. Every measurement formula is validated. We publish our accuracy methodology openly.
International by default
Ring standards differ by country. We support US, UK, EU, Indian, and Japanese size systems simultaneously — because jewelry crosses borders.