Author: ![Ring Size Chart & Guide [2025]: How to Measure Ring Size](https://plugins-media.makeupar.com/smb/blog/post/2025-10-02/webp_4443f0fb-aa84-4980-bc5b-895e95a75dc0.jpg)
Choosing the right ring size can be the difference between a comfortable fit and an expensive resizing. Many shoppers search for a ring size chart before making a purchase to avoid mistakes. In this guide, we’ll show you how to measure your ring size correctly, provide a detailed conversion chart, and introduce an AI/AR ring sizing tool that makes the process effortless.
How to Measure Your Ring Size
Before diving into charts and conversions, start with one of these simple at-home methods:
1. Measure with String
- Measure: Wrap a non-stretch string around the base of your finger.
- Determine: Mark the overlap point, lay it flat, and measure the length in millimeters.
- Tip: Don’t pull too tight—aim for a snug but comfortable fit.
- Check: Match your measurement to a ring size chart.
2. Measure with Paper
- Measure: Cut a thin strip of paper and wrap it around your finger.
- Determine: Mark where the paper overlaps.
- Tip: Keep the strip flat and untwisted for accuracy.
- Check: Measure the length in mm and convert using the chart.
Image suggestion: Paper strip wrapped around a finger, marked with a pen.
3. Measure with Ring
Perfect for surprise gifts:
- Measure: Borrow a ring your partner wears on the intended finger.
- Determine: Place it on a ruler and measure the inside diameter.
- Tip: Use a ring that fits comfortably—not too tight, not too loose.
- Check: Compare the diameter with a ring size conversion chart.
Image suggestion: Ring placed on a ruler with diameter overlay lines.
Pro Tip: Measure in the afternoon when fingers are largest. Avoid measuring after exercise or in cold temperatures.
👉 Want a faster way? Skip manual measuring and try our AI/AR Ring Size Tool, which scans your finger with your camera for instant accuracy.
Ring Size Chart & Conversion
| Diameter (mm) | US | FR | UK | JP |
|---|---|---|---|---|
| 13.5 | 2.5 | 43 | D 1/2 | 3 |
| 14.0 | 3 | 44 | F | 4 |
| 14.5 | 3.5 | 46 | G | 6 |
| 15.0 | 4 | 47 | G–H | 7 |
| 15.5 | 5 | 49 | I–J | 9 |
| 16.0 | 5.5 | 50 | J–K | 10 |
| 16.5 | 6 | 52 | L–M | 12 |
| 17.0 | 7 | 53 | N–O | 13 |
| 17.5 | 7.5 | 55 | O | 15 |
| 18.0 | 8 | 57 | O–P | 16 |
| 18.5 | 8.5 | 58 | P–Q | 18 |
| 19.0 | 9 | 60 | R–S | 19 |
| 19.5 | 9.5 | 61 | S–T | 21 |
| 20.0 | 10 | 63 | T–U | 22 |
| 20.5 | 11 | 64 | V–W | 24 |
| 21.0 | 11.5 | 66 | W–X | 25 |
| 21.5 | 12 | 67 | X–Y | 27 |
This size conversion table is for reference only.
Tips & Caveats
- Finger size changes during the day—measure in the afternoon.
- Temperature affects sizing: cold makes fingers smaller, heat makes them swell.
- Knuckle size matters—ensure the ring can slide over comfortably.
- Wider bands often require half a size larger.
What If the Ring Doesn’t Fit?
Even with best efforts, sizing can be tricky. Jewelers can resize most rings by stretching, cutting, or compressing. When in doubt, size up—resizing down is easier than making a ring bigger.
The Easiest Way - Ring Sizer Tool Online
Finding the right fit doesn’t need to be difficult. Use our AI/AR Ring Size Tool today to measure instantly, compare with the chart, and shop with confidence—no more guessing, no more returns.
Ring Size Chart FAQs
What is a ring size chart?
A reference table that converts inner diameter or circumference into standard sizes across countries.
How do I convert ring sizes between countries?
Use the international sizing chart above—for example, US size 6 ≈ UK L ≈ EU 52 ≈ Japan 12.
How accurate are printable ring sizers?
They’re convenient but depend on correct print scaling. Expect ±0.2 mm variation.
Can my ring size change over time?
Yes. Weight, age, pregnancy, or temperature can shift your size slightly.
What if I’m between two sizes?
Choose the larger size for comfort. Sizing inserts can make a loose ring tighter.
Does ring width affect sizing?
Yes, wider bands feel tighter. You may need half a size larger for bands above 6 mm.
