💍 Can You Measure Ring Size with Tape?
Yes. You can measure ring size with tape by wrapping a soft, flexible measuring tape around the base of the finger, reading the circumference in millimetres, and matching that number to a UK ring size chart. This method is quick and convenient when you do not have a jeweller's ring sizer available.
A flexible tailor's tape works best because it can follow the natural curve of the finger. The tape should sit snugly without squeezing the skin. If the tape is too loose, too tight or twisted, the result can move you into the wrong ring size.
For expensive jewellery, engagement rings or wide wedding bands, treat a home tape measurement as a useful starting point and confirm the final size with the retailer or a professional jeweller.
Convert Tape Circumference to UK Ring Size
Enter the finger circumference you read from the tape measure.
Measure the tape reading where the two ends meet. Do not add extra room unless the ring design or jeweller specifically recommends it.
Wrap, read and compare
This visual shows where to place the tape and how to read the finger circumference.
Place the Tape at the Finger Base
Position the tape where the ring will naturally sit, not too close to the palm or knuckle.
Wrap It Comfortably
Keep the tape flat and snug. It should touch the skin without leaving a deep indentation.
Read the Millimetres
Note the number where the tape overlaps. This is your finger circumference.
Check the Knuckle
If your knuckle is wider than the finger base, make sure the chosen size can still pass over it comfortably.
Use a soft measuring tape
A flexible sewing or tailor's tape is ideal. Avoid a rigid metal tape measure because it cannot follow the finger properly.
Measure the exact finger
Do not use another finger as a shortcut. Left and right hands can differ, especially on the dominant hand.
Wrap around the base
Place the tape at the normal ring position and keep it level all the way around.
Read the circumference
Record the tape reading in millimetres where the ends meet. If your tape shows centimetres, multiply by 10 to get millimetres.
Repeat the measurement
Take the reading two or three times. If the numbers vary, measure again later and use the most consistent result.
Match to the UK chart
Enter the circumference in the calculator above or use the full chart below to find the nearest UK letter size.
| UK Size | Inside Diameter | Finger Circumference | Circumference (in) |
|---|---|---|---|
| UK A | 12.04 mm | 37.8 mm | 1.49″ |
| UK A½ | 12.24 mm | 38.5 mm | 1.52″ |
| UK B | 12.45 mm | 39.1 mm | 1.54″ |
| UK B½ | 12.65 mm | 39.7 mm | 1.56″ |
| UK C | 12.85 mm | 40.4 mm | 1.59″ |
| UK C½ | 13.06 mm | 41.0 mm | 1.61″ |
| UK D | 13.26 mm | 41.7 mm | 1.64″ |
| UK D½ | 13.46 mm | 42.3 mm | 1.67″ |
| UK E | 13.67 mm | 42.9 mm | 1.69″ |
| UK E½ | 13.87 mm | 43.6 mm | 1.72″ |
| UK F | 14.07 mm | 44.2 mm | 1.74″ |
| UK F½ | 14.27 mm | 44.8 mm | 1.76″ |
| UK G | 14.48 mm | 45.5 mm | 1.79″ |
| UK G½ | 14.68 mm | 46.1 mm | 1.81″ |
| UK H | 14.88 mm | 46.8 mm | 1.84″ |
| UK H½ | 15.09 mm | 47.4 mm | 1.87″ |
| UK I | 15.29 mm | 48.0 mm | 1.89″ |
| UK J | 15.49 mm | 48.7 mm | 1.92″ |
| UK J½ | 15.70 mm | 49.3 mm | 1.94″ |
| UK K | 15.90 mm | 50.0 mm | 1.97″ |
| UK K½ | 16.10 mm | 50.6 mm | 1.99″ |
| UK L | 16.31 mm | 51.2 mm | 2.02″ |
| UK L½ | 16.51 mm | 51.9 mm | 2.04″ |
| UK M | 16.71 mm | 52.5 mm | 2.07″ |
| UK M½ | 16.92 mm | 53.1 mm | 2.09″ |
| UK N | 17.12 mm | 53.8 mm | 2.12″ |
| UK N½ | 17.32 mm | 54.4 mm | 2.14″ |
| UK O | 17.53 mm | 55.1 mm | 2.17″ |
| UK O½ | 17.73 mm | 55.7 mm | 2.19″ |
| UK P | 17.93 mm | 56.3 mm | 2.22″ |
| UK P½ | 18.14 mm | 57.0 mm | 2.24″ |
| UK Q | 18.34 mm | 57.6 mm | 2.27″ |
| UK Q½ | 18.54 mm | 58.3 mm | 2.30″ |
| UK R | 18.75 mm | 58.9 mm | 2.32″ |
| UK R½ | 18.95 mm | 59.5 mm | 2.34″ |
| UK S | 19.15 mm | 60.2 mm | 2.37″ |
| UK S½ | 19.35 mm | 60.8 mm | 2.39″ |
| UK T | 19.56 mm | 61.4 mm | 2.42″ |
| UK T½ | 19.76 mm | 62.1 mm | 2.44″ |
| UK U | 19.96 mm | 62.7 mm | 2.47″ |
| UK U½ | 20.17 mm | 63.4 mm | 2.50″ |
| UK V | 20.37 mm | 64.0 mm | 2.52″ |
| UK V½ | 20.57 mm | 64.6 mm | 2.54″ |
| UK W | 20.78 mm | 65.3 mm | 2.57″ |
| UK W½ | 20.98 mm | 65.9 mm | 2.59″ |
| UK X | 21.18 mm | 66.6 mm | 2.62″ |
| UK X½ | 21.39 mm | 67.2 mm | 2.65″ |
| UK Y | 21.59 mm | 67.8 mm | 2.67″ |
| UK Z | 21.79 mm | 68.5 mm | 2.70″ |
| UK Z½ | 22.00 mm | 69.1 mm | 2.72″ |
| UK Z+1 | 22.61 mm | 71.0 mm | 2.80″ |
| UK Z+2 | 23.01 mm | 72.3 mm | 2.85″ |
| UK Z+3 | 23.22 mm | 72.9 mm | 2.87″ |
| UK Z+4 | 23.62 mm | 74.2 mm | 2.92″ |
Note: Home tape measurements are practical estimates. Jewellers may round values differently, so verify the final size with the retailer before ordering.
Pulling Too Tight
A tight tape can make the finger look smaller and lead to a ring that pinches.
Leaving Too Much Slack
A loose tape may create an oversized result and a ring that spins or slips.
Ignoring the Knuckle
A ring must pass over the widest part of the finger, not just fit at the base.
Measuring Cold Hands
Cold fingers can temporarily measure smaller than they do under normal conditions.
Using the Wrong Hand
The same finger on the opposite hand may have a different circumference.
Forgetting Band Width
Wide rings can feel tighter than narrow bands even when the nominal size is the same.
Flexible tape is convenient because it gives a direct circumference reading. String can work, but it may stretch or compress and is easier to pull too tightly. Measuring the inside diameter of an existing ring can be very reliable when you already own a ring that fits the exact same finger.
If your tape result and existing-ring result disagree, repeat both measurements carefully. For valuable jewellery, a professional metal ring sizer is the best final check.