The free virtual ring sizer that actually works.
Most “virtual ring sizers” are just a printable PDF or a static image. RingSize.app is a true virtual ring sizer: it calibrates to your screen using a credit card or coin, so the on-screen ring matches real millimetres. Place a ring you own on the display, drag until the inner edges meet — that's your size.
Why this virtual ring sizer beats the rest
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Calibrated to your screen Most virtual ring sizers assume a generic DPI. We calibrate to yours using a credit card or coin, so accuracy is comparable to a jeweller’s mandrel.
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Works on phone, tablet, desktop A virtual ring sizer is only useful if it works where you are. Open ringsize.app in any modern browser — iPhone, Android, Mac, Windows.
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No app to install Truly browser-based. Free, no sign-up, no email, no download.
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Full US / UK / EU / JP conversion See your size in every standard at once, with diameter and circumference in mm for jewellers.
The virtual ring sizer — 30 seconds to your size.
Calibrate once with a credit card. Then place a ring you own on the screen, or measure your finger with a paper strip. Free, no sign-up.
The main ring sizer
The full guided flow — choose method, calibrate, measure, convert.
ReferenceInternational ring size chart
US, UK, EU, JP, IN, CN — every standard, side-by-side.
ToolVirtual ring sizer
Screen-calibrated alternative to a physical ring sizer kit.
ToolRing size calculator
Convert between US, UK, EU, JP — or from raw millimetres.
GuideHow to measure ring size
Three reliable methods, ranked by accuracy.
ArticlesAll ring sizing resources
Guides, tips and tutorials for getting the right fit.