Ring sizing guides

Sixteen step-by-step guides covering every way to measure a ring size: with a ring, without one, secretly, in six sizing systems, and around the problems that make rings not fit.

Guide

How to measure your ring size at home

Five ways to measure ring size at home, ranked by accuracy, plus the calibration step that decides whether any of them actually works.

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Guide

Ring size chart for US, UK, EU, Japan, China and Russia

The complete international ring size chart with millimetre diameters and circumferences, plus how to read it and which column your seller actually means.

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Guide

Ring size converter

Convert ring sizes between US, UK, EU/ISO, Japanese, Chinese and Russian systems instantly, plus the millimetre diameter every jeweller can work from.

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Guide

How to measure ring size without a ring sizer

The string and paper methods explained properly, including the error each one introduces and the fix that makes a phone screen more accurate than either.

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Guide

How to find her ring size without her knowing

Eight ways to get an engagement ring size secretly, ranked by how accurate and how risky each one is, plus what to order when you still are not sure.

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Guide

How to measure ring size using a ring you already own

The most accurate at-home method: measure the inner diameter of a ring that fits. Here is how to do it on screen, on paper, and with a caliper.

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Guide

How to measure your finger for a ring size

Measure a finger accurately when you have no ring to copy: the on-screen gauge method, the knuckle test, and when to take the reading.

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Guide

Virtual ring try-on: see a ring on your own hand

How AI virtual try-on works, what it can and cannot tell you about a ring, and how to shoot a hand photo that produces a genuinely useful preview.

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Guide

Average ring size for women and men

The most common ring sizes for women and men, what the distribution looks like, and how to use an average safely when you cannot measure.

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Guide

mm to ring size: diameter and circumference converted

Turn a millimetre measurement into a ring size. Full diameter and circumference chart, plus how to tell which of the two your number actually is.

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Guide

Printable ring sizers, and why they so often print wrong

How to use a printable ring sizer without the scaling error that ruins most of them, plus the credit-card check that verifies any printed or on-screen scale.

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Guide

Men’s ring size chart and how to measure

The men’s ring size chart from US 8 to 13 with millimetres, why men’s bands usually need a size up, and how to measure a man’s finger properly.

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Guide

Wide band ring sizing: when to size up, and by how much

Wide bands fit tighter at the same size. Here is the adjustment table by band width, why it happens, and how comfort fit changes the answer.

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Guide

Ring sizing when your knuckle is bigger than your finger

Measure both the knuckle and the base, pick a size between the two, and stop the ring spinning. The complete fix for large-knuckle ring sizing.

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Guide

Engagement ring size guide

How to get an engagement ring size right when you only get one attempt: secret measuring, what to order if you cannot, and the resize questions to ask first.

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Guide

US to UK ring size conversion

Convert US ring size numbers to UK letters and back. Full chart from US 3 to 13, plus the half-letter rule that trips most conversions up.

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Ring Sizer app icon

Measure it instead of reading about it

Ring Sizer is free on the App Store: calibrated to your device, offline, six sizing systems.