Finding the right ring size ensures both comfort and beauty. At Fascinating Diamonds, every ring is crafted using standard US sizing. Use the conversion chart below to see how US sizes align with finger circumference and international measurements. The same sizing applies to engagement rings, wedding bands, and fashion rings.
International Size Chart
| Inside Diameter | Inside Circumference | Sizes | |||||||
| MM | Inches | MM | Inches | British & Australian | US & Canada | French & Russian | German | Japanese | Swiss |
| 9.91 | 0.390 | 31.13 | 1.22 | - | 0000 | - | - | - | - |
| 10.72 | 0.442 | 33.68 | 1.39 | - | 00 | - | - | - | - |
| 11.53 | 0.454 | 36.22 | 1.43 | - | 0 | - | - | - | - |
| 11.95 | 0.474 | 37.54 | 1.49 | A | 1/2 | - | - | - | - |
| 12.18 | 0.482 | 38.26 | 1.51 | A 1/2 | 3/4 | - | - | - | - |
| 12.37 | 0.487 | 38.86 | 1.53 | B | 1 | - | - | 1 | - |
| 12.60 | 0.496 | 39.58 | 1.56 | B 1/2 | 1 1/4 | - | - | - | - |
| 12.78 | 0.503 | 40.15 | 1.58 | C | 1 1/2 | - | - | - | - |
| 13.00 | 0.512 | 40.84 | 1.61 | C 1/2 | 1 3/4 | - | - | - | - |
| 13.21 | 0.520 | 41.50 | 1.63 | D | 2 | 41 1/2 | 13 1/2 | 2 | 1 1/2 |
| 13.41 | 0.528 | 42.13 | 1.66 | D 1/2 | 2 1/4 | - | - | - | - |
| 13.61 | 0.536 | 42.76 | 1.68 | E | 2 1/2 | 42 3/4 | 13 3/4 | 3 | 2 3/4 |
| 13.83 | 0.544 | 43.45 | 1.71 | E 1/2 | 2 3/4 | - | - | - | - |
| 14.05 | 0.553 | 44.14 | 1.74 | F | 3 | 44 | 14 | 4 | 4 |
| 14.15 | 0.557 | 44.45 | 1.75 | F 1/2 | 3 1/8 | - | - | - | - |
| 14.25 | 0.561 | 44.77 | 1.76 | F 3/4 | 3 1/4 | - | - | - | - |
| 14.36 | 0.565 | 45.11 | 1.77 | G | 3 3/8 | 45 1/4 | - | 5 | 5 1/4 |
| 14.45 | 0.569 | 45.40 | 1.79 | G 1/4 | 3 1/2 | - | 14 1/2 | - | - |
| 14.56 | 0.573 | 45.74 | 1.80 | G 1/2 | 3 5/8 | - | - | 6 | - |
| 14.65 | 0.577 | 46.02 | 1.81 | H | 3 3/4 | 46 1/2 | - | - | 6 1/2 |
| 14.86 | 0.585 | 46.68 | 1.84 | H 1/2 | 4 | - | 15 | 7 | - |
| 15.04 | 0.592 | 47.25 | 1.86 | I | 4 1/4 | 47 3/4 | - | - | 7 3/4 |
| 15.27 | 0.601 | 47.97 | 1.89 | I 1/2 | 4 1/2 | - | 15 1/4 | 8 | - |
| 15.40 | 0.606 | 48.38 | 1.90 | J | 4 5/8 | 49 | 15 1/2 | - | 9 |
| 15.53 | 0.611 | 48.79 | 1.92 | J 1/4 | 4 3/4 | - | - | - | - |
| 15.70 | 0.618 | 49.32 | 1.94 | J 1/2 | 5 | - | 15 3/4 | 9 | - |
| 15.80 | 0.622 | 49.64 | 1.95 | K | 5 1/8 | 50 | - | - | 10 |
| 15.90 | 0.626 | 49.95 | 1.97 | K 1/4 | 5 1/4 | - | - | - | - |
| 16.00 | 0.630 | 50.27 | 1.98 | K 1/2 | 5 3/8 | - | - | 10 | - |
| 16.10 | 0.634 | 50.58 | 1.99 | L | 5 1/2 | 51 3/4 | 16 | - | 11 3/4 |
| 16.30 | 0.642 | 51.21 | 2.02 | L 1/4 | 5 3/4 | - | - | - | - |
| 16.41 | 0.646 | 51.55 | 2.03 | L 1/2 | 5 7/8 | - | - | - | - |
| 16.51 | 0.650 | 51.87 | 2.04 | M | 6 | 52 3/4 | 16 1/2 | 12 | 12 3/4 |
| 16.71 | 0.658 | 52.50 | 2.07 | M 1/2 | 6 1/4 | - | - | - | - |
| 16.92 | 0.666 | 53.16 | 2.09 | N | 6 1/2 | 54 | 17 | 13 | 14 |
| 17.13 | 0.674 | 53.82 | 2.12 | N 1/2 | 6 3/4 | - | - | - | - |
| 17.35 | 0.683 | 54.51 | 2.15 | O | 7 | 55 1/4 | 17 1/4 | 14 | 15 1/4 |
| 17.45 | 0.687 | 54.82 | 2.16 | O 1/2 | 7 1/4 | - | - | - | - |
| 17.75 | 0.699 | 55.76 | 2.20 | P | 7 1/2 | 56 1/2 | 17 3/4 | 15 | 16 1/2 |
| 17.97 | 0.707 | 56.45 | 2.22 | P 1/2 | 7 3/4 | - | - | - | - |
| 18.19 | 0.716 | 57.15 | 2.25 | Q | 8 | 57 3/4 | 18 | 16 | 17 3/4 |
| 18.35 | 0.722 | 57.65 | 2.27 | Q 1/2 | 8 1/4 | - | - | - | - |
| 18.53 | 0.729 | 58.21 | 2.29 | Q 3/4 | 8 1/2 | - | 18 1/2 | 17 | - |
| 18.61 | 0.733 | 58.47 | 2.30 | R | 8 5/8 | 59 | - | - | 19 |
| 18.69 | 0.736 | 58.72 | 2.31 | R 1/4 | 8 3/4 | - | - | - | - |
| 18.80 | 0.740 | 59.06 | 2.32 | R 1/2 | 8 7/8 | - | - | - | - |
| 18.89 | 0.748 | 59.34 | 2.35 | R 3/4 | 9 | - | 19 | 18 | - |
| 19.10 | 0.752 | 60.00 | 2.36 | S | 9 1/8 | 60 1/4 | - | - | 20 1/4 |
| 19.22 | 0.757 | 60.38 | 2.38 | S 1/4 | 9 1/4 | - | - | - | - |
| 19.31 | 0.760 | 60.66 | 2.39 | S 1/2 | 9 3/8 | - | - | - | - |
| 19.41 | 0.764 | 60.98 | 2.40 | S 3/4 | 9 1/2 | - | 19 1/2 | 19 | - |
| 19.51 | 0.768 | 61.29 | 2.41 | T | 9 5/8 | 61 1/2 | - | - | 21 1/2 |
| 19.62 | 0.772 | 61.64 | 2.43 | T 1/4 | 9 3/4 | - | - | - | - |
| 19.84 | 0.781 | 62.33 | 2.45 | T 1/2 | 10 | - | 20 | 20 | - |
| 20.02 | 0.788 | 62.89 | 2.48 | U | 10 1/4 | 62 3/4 | - | 21 | 22 3/4 |
| 20.20 | 0.797 | 63.46 | 2.50 | U 1/2 | 10 1/2 | - | 20 1/4 | 22 | - |
| 20.32 | 0.800 | 63.84 | 2.51 | V | 10 5/8 | 63 | - | - | 23 3/4 |
| 20.44 | 0.805 | 64.21 | 2.53 | V 1/4 | 10 3/4 | - | - | - | - |
| 20.68 | 0.814 | 64.97 | 2.56 | V 1/2 | 11 | - | 20 3/4 | 23 | - |
| 20.76 | 0.817 | 65.22 | 2.57 | W | 11 1/8 | 65 | - | - | 25 |
| 20.85 | 0.821 | 65.50 | 2.58 | W 1/4 | 11 1/4 | - | - | - | - |
| 20.94 | 0.824 | 65.78 | 2.59 | W 1/2 | 11 3/8 | - | - | - | - |
| 21.08 | 0.830 | 66.22 | 2.61 | W 3/4 | 11 1/2 | - | 21 | 24 | - |
| 21.18 | 0.834 | 66.54 | 2.62 | X | 11 5/8 | 66 1/4 | - | - | 26 1/4 |
| 21.24 | 0.836 | 66.73 | 2.63 | X 1/4 | 11 3/4 | - | - | - | - |
| 21.30 | 0.839 | 66.92 | 2.64 | X 1/2 | 11 7/8 | - | - | - | - |
| 21.49 | 0.846 | 67.51 | 2.66 | Y | 12 | 67 1/2 | 21 1/4 | 25 | 27 1/2 |
| 21.69 | 0.854 | 68.14 | 2.68 | Y 1/2 | 12 1/4 | - | - | - | - |
| 21.89 | 0.862 | 68.77 | 2.71 | Z | 12 1/2 | 68 3/4 | 21 3/4 | 26 | 28 3/4 |
| 22.10 | 0.870 | 69.43 | 2.73 | Z +1/2 | 12 3/4 | - | - | - | - |
| 22.33 | 0.879 | 70.15 | 2.76 | Z+1 | 13 | - | 22 | 27 | - |
| 22.60 | 0.890 | 71.00 | 2.80 | Z+1.5 | 13.5 | - | - | - | - |
| 22.69 | 0.893 | 71.28 | 2.81 | Z+2 | - | - | - | - | - |
| 22.92 | 0.902 | 72.00 | 2.83 | Z+2.5 | - | - | - | - | - |
| 23.06 | 0.908 | 72.45 | 2.85 | Z+3 | - | - | - | - | - |
| 23.24 | 0.915 | 73.01 | 2.87 | Z+3.5 | - | - | - | - | - |
| 23.47 | 0.924 | 73.73 | 2.90 | Z+4 | - | - | - | - | - |
| 23.55 | 0.927 | 73.98 | 2.91 | Z+4.5 | - | - | - | - | - |
| 23.87 | 0.940 | 74.99 | 2.95 | Z+5 | - | - | - | - | - |
| 24.27 | 0.956 | 76.25 | 3.00 | Z+6 | - | - | - | - | - |
How to Measure Your Ring Size at Home
If you’re not sure about your ring size, you can measure it right at home with simple tools. Try one of these quick methods:
1. DIY String or Paper Method
What you’ll need:
- A piece of string or a thin strip of paper
- Pen or marker
- Ruler
Steps:
- Wrap the string around the base of your finger.
- Mark where the ends overlap.
- Measure the marked length in millimeters.
- Match it to the corresponding US size in the chart above.
2. Printable Ring Sizer
What you’ll need:
- Printer
- Scissors
Steps:
- Print the Fascinating Diamonds ring sizer on standard 8.5" x 11" paper. Make sure scaling is set to 100%.
- Cut along the lines as directed.
- Wrap the sizer around your finger and read the number that lines up through the slit.
- If you fall between two sizes, choose the slightly larger one or contact us for a quarter-size option.
3. Measure an Existing Ring
What you’ll need:
- Printer
- A ring that already fits well
Steps:
- Print our ring size guide at actual scale.
- Place your ring over each circle until the inner edge matches one of them.
- That number is your size. If it sits between two circles, order the quarter size between them.
How a Ring Should Fit
If your measurement falls between two sizes, choose the larger one. Fingers can change size throughout the day due to temperature or swelling. A tight ring can be uncomfortable, but a slightly loose one can be easily adjusted later.
Need precision? We can craft your ring in quarter sizes for a flawless fit.
Helpful Ring Sizing Tips
- Measure the finger you’ll wear the ring on, since dominant hands are usually a bit larger.
- Rings with wide bands fit tighter. For designs over 4mm, go up half a size.
- Measure your finger at room temperature—cold fingers shrink and warm fingers expand.
- The best time to measure is midday or evening, when your fingers are at their natural size.
- If your knuckles are prominent, measure both the base and knuckle and select a size in between.
Can All Rings Be Resized?
Some designs can’t be resized due to their structure. Eternity bands, open bands, and alternative metals usually can’t be adjusted. This information is clearly mentioned on each product page.
If resizing isn’t possible, we offer a free exchange within 30 days to help you get the perfect fit.
Free Resizing and Exchange Policy
We want your ring to fit perfectly. That’s why Fascinating Diamonds offers:
- Free resizing within 30 days for eligible styles
- Free size exchanges within 30 days of purchase
Whether it’s an engagement ring or a wedding band, we’ll make sure it feels just right.
Frequently Asked Questions
1. How do I know my ring size if I’ve never been measured before?
You can measure your ring size at home using a printable ring sizer or the string and ruler method. Simply wrap a string around your finger, mark where it overlaps, and match the measurement to our US size chart.
2. Are Fascinating Diamonds rings made in standard US sizes?
Yes, all Fascinating Diamonds rings are crafted using standard US sizing. You can use our conversion chart to compare US sizes with international measurements or finger circumferences.
3. What should I do if I fall between two ring sizes?
If your measurement falls between two sizes, we recommend choosing the slightly larger size. Fingers naturally swell and shrink throughout the day, so a bit of extra room ensures comfort.
4. Can I order a quarter size?
Absolutely. Fascinating Diamonds offers quarter-size options for most designs to ensure a precise and comfortable fit. You can contact our team for assistance with custom sizing.
5. Can all rings be resized?
Not all styles can be resized. Rings such as eternity bands, open designs, or those made with alternative metals may not be adjustable. Each product page clearly indicates whether resizing is possible.
6. What should I do if my ring doesn’t fit when it arrives?
We offer free resizing within 30 days for eligible styles and free size exchanges within 30 days of purchase. Contact our support team, and we’ll guide you through the process.
7. How tight should a ring fit?
A properly fitting ring should slide over your knuckle with light resistance and sit snugly without feeling tight. It shouldn’t leave marks or slip off easily.
8. Does ring width affect sizing?
Yes. Rings with wider bands (over 4mm) fit more tightly than thin bands. If you’re ordering a wide design, it’s best to go half a size larger for a comfortable fit.
9. When is the best time of day to measure my ring size?
The ideal time to measure your ring size is midday or evening when your fingers are at their normal size. Avoid measuring early in the morning or in cold weather, as fingers may be smaller then.
10. What if I’m buying a ring as a surprise?
Try borrowing a ring your partner already wears on the same finger and compare it using our printable size chart. If the fit isn’t perfect, our free resizing and exchange policy ensures it can easily be adjusted later.