Ring Size Calculator Online
All in one ring sizer to get your ring size quickly
Get your screen size
- Put your credit card on the screen
- Slide until the rectangle matches your card width
- Click Confirm to lock the screen size
Measure your ring
Please complete Step 1 first
Get your ring size
Please complete Step 2 first
Comprehensive International Ring Size Chart
Already have a measurement? Use the chart below to understand how it fits into international standards.
| Diameter (mm) | Circumference (mm) | US & Canada | UK & Australia | EU | Japan & Singapore | Hong Kong | Switzerland |
|---|---|---|---|---|---|---|---|
| 14.1 | 44.1 | 3 | F | 44 | 4 | 7 | 4 |
| 14.3 | 44.8 | 3.25 | G | 45 | 5 | 7.5 | 5 |
| 14.4 | 45.4 | 3.5 | G 1/2 | 45.5 | 5.5 | 8 | 5.5 |
| 14.7 | 46.0 | 3.75 | H | 46 | 6 | 8.5-9 | 6 |
| 14.9 | 46.7 | 4 | H 1/2 | 47 | 7 | 9.5 | 7 |
| 15.0 | 47.3 | 4.25 | I | 47.5 | 7.5 | 10 | 7.5 |
| 15.3 | 48.0 | 4.5 | J | 48 | 8 | 10.5 | 8 |
| 15.4 | 48.4 | 4.75 | J 1/2 | 48.5 | 8.5 | 11 | 8.5 |
| 15.7 | 49.3 | 5 | K 1/2 | 49.5 | 9 | 11.5-12 | 9.5 |
| 15.9 | 50.0 | 5.25 | L | 50 | 9.5 | 12.5 | 10 |
| 16.1 | 50.6 | 5.5 | L 1/2 | 50.5 | 10.5 | 13 | 10.5 |
| 16.3 | 51.2 | 5.75 | M | 51 | 11 | 13.5 | 11 |
| 16.5 | 51.9 | 6 | M 1/2 | 52 | 12 | 14-14.5 | 12 |
| 16.7 | 52.5 | 6.25 | N | 52.5 | 12.5 | 15 | 12.5 |
| 16.9 | 53.2 | 6.5 | N 1/2 | 53 | 13 | 15.5 | 13 |
| 17.1 | 53.8 | 6.75 | O | 54 | 13.5 | 16 | 14 |
| 17.3 | 54.4 | 7 | O 1/2 | 54.5 | 14 | 16.5 | 14.5 |
| 17.5 | 55.1 | 7.25 | P | 55 | 14.5 | 17 | 15 |
| 17.7 | 55.7 | 7.5 | P 1/2 | 56 | 15 | 17.5 | 16 |
| 17.9 | 56.3 | 7.75 | Q | 56.5 | 16 | 18 | 16.5 |
| 18.1 | 57.0 | 8 | Q 1/2 | 57 | 16.5 | 18.5 | 17 |
| 18.3 | 57.6 | 8.25 | R | 57.5 | 17 | 19 | 17.5 |
| 18.5 | 58.3 | 8.5 | R 1/2 | 58.5 | 17.5 | 19.5-20 | 18.5 |
| 18.8 | 58.9 | 8.75 | S | 59 | 18 | 20.5 | 19 |
| 18.9 | 59.5 | 9 | S 1/2 | 59.5 | 18.5 | 21 | 19.5 |
| 19.1 | 60.2 | 9.25 | T | 60 | 19 | 21.5 | 20 |
| 19.4 | 60.8 | 9.5 | T 1/2 | 61 | 19.5 | 22 | 21 |
| 19.6 | 61.5 | 9.75 | U | 61.5 | 20 | 22.5-23 | 21.5 |
| 19.8 | 62.1 | 10 | U 1/2 | 62 | 21 | 23.5 | 22 |
| 20.0 | 62.7 | 10.25 | V | 63 | 22 | 24 | 23 |
| 20.2 | 63.4 | 10.5 | V 1/2 | 63.5 | 22.5 | 24.5 | 23.5 |
| 20.4 | 64.0 | 10.75 | W | 64 | 23 | 25 | 24 |
| 20.6 | 64.6 | 11 | W 1/2 | 64.5 | 24 | 25.5-26 | 24.5 |
| 20.8 | 65.3 | 11.25 | X | 65.5 | 25 | 26.5 | 25.5 |
| 21.0 | 65.9 | 11.5 | X 1/2 | 66 | 25.5 | 27 | 26 |
| 21.2 | 66.5 | 11.75 | Y | 66.5 | 26 | 27.5 | 26.5 |
| 21.4 | 67.2 | 12 | Y 1/2 | 67 | 27 | 28-28.5 | 27 |
| 21.6 | 67.8 | 12.25 | Z | 68 | 27.5 | 29 | 28 |
| 21.8 | 68.5 | 12.5 | Z 1/2 | 68.5 | 28 | 29.5-30 | 28.5 |
| 22.0 | 69.1 | 12.75 | Z+1 | 69 | 29 | 30.5 | 29 |
| 22.2 | 69.7 | 13 | Z+1 1/2 | 70 | 30 | 31-31.5 | 30 |
| 22.4 | 70.4 | 13.25 | Z+2 | 70.5 | 31 | 32 | 30.5 |
| 22.6 | 71.0 | 13.5 | Z+2 1/2 | 71 | 32 | 32.5-33 | 31 |
Values are based on commonly referenced international charts. Manufacturers may vary; use as guidance.
- US/CA:
- Numeric scale with half sizes (e.g., 6, 6.5).
- UK/AU:
- Alphabetic scale with half-steps (e.g., M, M½).
- EU:
- Typically inner circumference in mm (e.g., 52, 53).
- JP/SG:
- Numeric scale (e.g., 12, 13).
- HK/CH:
- Local numeric scales that may differ from JP.
Your Ring Sizing Toolkit
Jump to the converter, printable sizer, visualizer, or back to the ring-size hub.
Guides & Tips for Ring Size Calculation
Follow these steps to measure and double-check your ring size on this calculator.
1. Calibrate your screen and pick a starting size
- Use a standard credit or bank card to calibrate your screen before you start.
- Make sure the on‑screen card outline matches your physical card as closely as possible.
- Start from the size that seems closest to your current ring or brand chart, then fine‑tune from there.
2. Measure at the right time and compare a few sizes
- Measure at the end of the day when your fingers are slightly warm and not just after exercise.
- If the ring outline sits between two sizes, try both and choose the one that feels comfortable for sliding over the knuckle.
- Repeat the measurement 2–3 times and compare the results instead of trusting a single reading.
3. Adjust for wide bands and confirm before you buy
- For wide bands or comfort‑fit styles, consider going about half a size up from your first result.
- Save a screenshot or PNG of your result so you can compare it with jeweler or brand charts later.
- Whenever possible, confirm your final choice with a physical ring sizer or local jeweler before you place an order.
4. Ways to measure your ring size at home
- Use an existing ring that fits well and match its inner diameter on the screen or with a printable chart.
- Wrap a strip of paper or string around your finger, mark the overlap, then measure the length in millimeters.
- Use a dedicated ring sizer or multi‑ring gauge if you have access to one, and keep the mm values for reference.
5. Comparing different sizing methods
- Screen‑based tools, printable sizers, and physical ring gauges may give slightly different results.
- Try at least two methods and see if they point to the same size or neighboring sizes.
- Treat online tools as a way to narrow down your range, then use a physical check for the final decision when you can.
6. What can change your finger size
- Temperature, time of day, salt intake, and recent exercise can all make your fingers swell or shrink.
- Measure on a day and time that feels typical for you, not right after heavy exercise or in very cold weather.
- If your size often fluctuates, choose a size that feels secure but not tight on your larger days.
About Sizepedia
A data-driven size knowledge base providing standards, datasets and practical tools.
Sizepedia.com is a size-focused encyclopedia and toolkit: we collect and curate public standards, manufacturer size charts, and industry references to build consistent conversion tables and reference data that clarify how different systems correspond. We currently prioritize and publish features for ring sizing, including online measurement tools, international conversion tables, and brand mappings. Over time we will expand to footwear, apparel, and additional sizing categories to deliver more data and practical tools. Our resources are provided as a best-effort guide to help you choose sizes with confidence; when an exact fit matters, combine our guidance with local measurement or manufacturer recommendations for final confirmation.
Want more sizes or brands covered? Tell us — help Sizepedia.com grow.