To measure your ring size with a fabric tape measure, wrap the tape around the base of your finger, keep it snug but not tight, and read the number where the tape overlaps. That number is your finger’s circumference. Match it to the chart below to find your ring size. For example, 57 mm (2.24 inches) is a US size 8.
A soft fabric tape measure is one of the easiest ways to find your ring size at home. This guide shows you exactly how to do it, how to convert your measurement and how to avoid the common mistakes that lead to the wrong size.
What You Need
- A soft fabric or vinyl tape measure with millimeter markings, the kind used for sewing.
- A pen to mark where the tape overlaps.
- A ruler to check that your tape has not stretched.
- A thin strip of paper or string as a backup if you do not have a tape.
Do not use a metal tape measure. It is too stiff to wrap around a finger and gives a measurement that is too large.
How to Measure Ring Size With a Fabric Tape Measure: 4 Steps
Step 1: Check Your Tape
Fabric tapes can stretch with age. Lay your tape next to a ruler and check that 10 cm on the tape matches 10 cm on the ruler. If it does not, use a strip of paper instead.
Step 2: Wrap the Tape Around Your Finger
Wrap the tape around the base of the finger you will wear the ring on, where the ring will sit. Keep it flat and level, not twisted or angled. Pull it snug so it does not slip, but not so tight that it presses into your skin.
Step 3: Read the Measurement
Look at where the end of the tape meets the rest of the tape and read the number in millimeters. If your tape only shows inches, multiply the inches by 25.4 to get millimeters.
Step 4: Match It to Your Ring Size
Find your measurement in the chart below, or enter it into our free ring size chart calculator to convert it to US, UK or EU sizes. If your number falls between two sizes, choose the larger one.
Ring Size Chart by Circumference
Your tape measure gives you the circumference of your finger. Use this chart to turn it into a US ring size.
| Circumference (mm) | Circumference (inches) | US size |
|---|---|---|
| 46.8 mm | 1.84 in | 4 |
| 48.0 mm | 1.89 in | 4.5 |
| 49.3 mm | 1.94 in | 5 |
| 50.6 mm | 1.99 in | 5.5 |
| 51.9 mm | 2.04 in | 6 |
| 53.1 mm | 2.09 in | 6.5 |
| 54.4 mm | 2.14 in | 7 |
| 55.7 mm | 2.19 in | 7.5 |
| 57.0 mm | 2.24 in | 8 |
| 58.3 mm | 2.30 in | 8.5 |
| 59.5 mm | 2.34 in | 9 |
| 60.8 mm | 2.39 in | 9.5 |
| 62.1 mm | 2.44 in | 10 |
| 63.4 mm | 2.50 in | 10.5 |
| 64.6 mm | 2.54 in | 11 |
| 65.9 mm | 2.59 in | 11.5 |
| 67.2 mm | 2.65 in | 12 |
| 68.5 mm | 2.70 in | 12.5 |
| 69.7 mm | 2.74 in | 13 |
Source: JK Diamonds Institute international ring size chart. Brands can vary slightly, so also check the seller’s own chart.
Measured around 57 mm? That is one of the most common sizes. Learn more about the size 8 ring in the USA.
No Tape Measure? Use Paper or String
- Cut a thin strip of paper about 1 cm wide, or use a piece of non stretchy string.
- Wrap it around the base of your finger and mark where it overlaps with a pen.
- Lay it flat on a ruler and measure from the end to the mark in millimeters.
- Match the number to the chart above.
String can stretch and is easy to pull too tight, so paper usually gives a better result. You can also use a printable ring sizer, which has the scale printed on it.
Tips for an Accurate Measurement
- Measure at the end of the day, when fingers are usually at their largest.
- Measure at room temperature. Fingers swell in heat and shrink in cold.
- Measure three times, ideally on different days, and use the most common result.
- Measure the right hand. Fingers on your dominant hand are often slightly bigger.
- Check your knuckle. If your knuckle is much bigger than the base of your finger, measure both and choose a size between the two that can still slide over the knuckle.
- Think about band width. Wide bands feel tighter, so go up about a half size for bands of 6 mm or more. See our 6mm vs 8mm ring size guide.
Common Mistakes to Avoid
- Reading inches as millimeters, or the other way around.
- Using a metal or stretched tape measure.
- Pulling the tape too tight, which gives a size that is too small.
- Measuring the knuckle or fingertip instead of the base of the finger.
- Measuring right after a hot shower, exercise or time in the cold.
Understanding Ring Size Systems
Your millimeter measurement works with every sizing system. Here is how a 57 mm finger (US size 8) shows up around the world:
| Country or region | System | Size for 57 mm |
|---|---|---|
| United States and Canada | Numbers with half sizes | 8 |
| UK, Ireland and Australia | Letters | P½ |
| Europe | Circumference in mm | 57 |
Is a Tape Measure Accurate Enough?
A fabric tape measure is accurate enough for most everyday rings when you measure carefully. For an engagement ring, wedding band or expensive piece, confirm your size with a set of plastic sizing rings or a jeweler, because they let you feel how a real ring fits.
Building a ring stack? Several rings on one finger can feel tighter than one. Our guide on how to layer jewelry explains how to size and style a stack.
Frequently Asked Questions
Can I measure my ring size with a tape measure?
Yes. A soft fabric tape measure gives you your finger circumference in millimeters, which you can match to a ring size chart.
What ring size is 57 mm?
A 57 mm finger circumference is a US size 8.
What ring size is 2.5 inches?
A circumference of 2.5 inches is about 63.5 mm, which is close to a US size 10.5.
Should the tape be tight or loose?
Snug. It should sit flat against your skin without pressing in, and you should be able to slide it a little.
What if I am between two sizes?
Choose the larger size, especially for wide bands. A slightly loose ring can be fixed with sizing beads.
Is it better to measure in the morning or evening?
Evening. Fingers are usually smallest in the morning and largest at the end of the day.
Final Thoughts
Learning how to measure ring size with a fabric tape measure takes just a few minutes. Check your tape, wrap it snugly around the base of your finger, read the millimeters and match them to the chart.
Measure a few times at the end of the day, and for important rings confirm your size before you buy. That way your ring will fit comfortably from the first day you wear it.
