Measure ring size at homeInch conversion
How to measure ring size at home in inches
If your ruler or tape measure uses inches, convert the circumference to millimeters first. One inch equals 25.4 mm.
Calibrate your screen
Place a real bank card on your screen. Align its top-left corner with the virtual card, then use the slider until the virtual card's left vertical edge matches exactly.
Standard bank card short edge: 53.98 mm. No camera, no upload, no card number needed.
Measure finger circumference
Wrap paper or string around the finger base, mark the overlap, then lay it straight on the ruler and drag the marker so the red line meets the end.
If your measurement falls between two sizes, choose the larger size. For wide bands or fingers that swell easily, choose a slightly larger size.
Quick answer: How to measure ring size at home in inches
Measure the finger circumference in inches, multiply by 25.4 to get millimeters, then use the first chart row equal to or larger than that value.
- Measure the paper strip or tape reading in inches.
- Multiply inches by 25.4.
- Use the millimeter circumference in the ring size chart.
Inches to ring size calculator
Enter circumference inches, or switch the unit to diameter inches if you measured an existing ring.
If your measurement falls between two sizes, choose the larger size.
How to measure your finger
2.14 inches equals about 54.4 mm.
Inch reading
Measure the paper strip or tape reading in inches.
Wrap and mark
Multiply inches by 25.4.
Choose the larger row
Round the purchase recommendation up, not down.
Measure finger circumference in inches
Read the length around the finger base. Do not use the flat width of the finger, because ring sizes are based on the inside circumference.
Inches to US ring size chart
Inches can be useful for US users, but the underlying calculation should still use millimeters for consistent international conversion.
Diameter vs circumference in inches
Circumference is the length around your finger. Diameter is calculated from circumference and should not be treated as a country size.
Ring size chart for this method
This table shows common conversion rows. If your measurement sits between two rows, use the larger recommended size for purchase.
| Circumference mm | Diameter mm | ISO / EU | US / CA | UK / AU | JP / CN | IT / ES / CH | RU |
|---|---|---|---|---|---|---|---|
| 44.2 | 14.1 | 44 | 3 | F | 4 | 4 | 14 |
| 45.5 | 14.5 | 46 | 3.5 | G | 5 | 5¼ | 14.5 |
| 46.8 | 14.9 | 47 | 4 | H | 7 | 6½ | 15 |
| 48.0 | 15.3 | 48 | 4.5 | I | 8 | 7¾ | 15.25 |
| 49.3 | 15.7 | 49 | 5 | J½ | 9 | 9 | 15.75 |
| 50.6 | 16.1 | 50.5 | 5.5 | K½ | 10 | 10¼ | 16.25 |
| 51.9 | 16.5 | 52 | 6 | L½ | 12 | 11½ | 16.5 |
| 53.1 | 16.9 | 53 | 6.5 | M½ | 13 | 12¾ | 17 |
| 54.4 | 17.3 | 54.5 | 7 | N½ | 14 | 14 | 17.25 |
| 55.7 | 17.7 | 56 | 7.5 | O½ | 15 | 15¼ | 17.75 |
| 57.0 | 18.1 | 57 | 8 | P½ | 16 | 16½ | - |
| 58.3 | 18.6 | 58.5 | 8.5 | Q½ | 17 | 17¾ | 18.5 |
| 59.5 | 18.9 | 60 | 9 | R½ | 18 | 19 | 19 |
| 60.8 | 19.4 | 61 | 9.5 | S½ | 19 | 20¼ | 19.5 |
| 62.1 | 19.8 | 62 | 10 | T½ | 20 | 21½ | 19.75 |
| 63.4 | 20.2 | 63.5 | 10.5 | U½ | 22 | 22¾ | - |
| 64.6 | 20.6 | 65 | 11 | V½ | 23 | 24 | 20.75 |
| 65.9 | 21.0 | 66 | 11.5 | W½ | 24 | 25¼ | 21 |
| 67.2 | 21.4 | 67.5 | 12 | X½ | 25 | 26½ | 21.5 |
| 68.5 | 21.8 | 69 | 12.5 | Z | 26 | 27¾ | 21.75 |
| 69.7 | 22.2 | 70 | 13 | - | 27 | 29 | 22 |
Conversion examples
| Input | Millimeters | Recommendation |
|---|---|---|
| 2.00 in | 50.8 mm | US 5.75 / EU 51 |
| 2.14 in | 54.4 mm | US 7 / EU 54.5 |
| 2.44 in | 62.0 mm | US 10 / EU 62 |
FAQ
How many inches is a size 7 ring?
In this chart, the recommended US 7 row is 54.4 mm circumference, which is about 2.14 inches.
Should I measure diameter or circumference in inches?
Measure circumference for your finger. Measure diameter only when you are using an existing ring that already fits.
Should I size up if I am between two ring sizes?
Yes. For online buying, choose the larger listed size when your measurement falls between two rows. A ring that is slightly loose is easier to adjust than one that will not pass the knuckle.
Is circumference or diameter better for ring sizing?
Circumference is safer for measuring a finger at home. Diameter is useful when measuring an existing ring, but it should be converted back to circumference before choosing a purchase size.
When should I measure my finger?
Measure near the end of the day at normal body temperature. Cold hands can shrink and hot weather can make fingers swell.