How to measure ring size at home
The easiest way to find your ring size at home is to loop a strip of paper or a piece of string around your finger, then measure its length in millimetres. A ring you already have that sits well on the right finger can point you to your size too. Whichever way you choose, measure more than once at different times of day, since your fingers swell and shrink a little as the day goes on.
Measure your ring size Printable ring sizer
The paper or string method
You only need a strip of paper or a length of string, a pen, and a millimetre ruler. Blue Nile, a large online jeweller, lays it out like this.
- Wrap the paper or string round the base of your finger.
- Use the pen to mark the spot where the two ends meet.
- Straighten it out, then use the ruler to read the millimetres from the end to the mark.
That length is the distance around your finger. Open the ring sizer on the home page, tap My finger and type the number, and your size appears straight away.
Can a ring you already have show your size?
If a ring already fits the finger you're buying for, it can guide you. The simplest way is to lay it on the circle in the ring sizer and make the circle match its inside edge. You can also measure straight across the inside with a ruler, or lay it on the circles of the printable sheet.
The ring size chart shows what each measurement means in every country.
Measuring on your phone screen
Phones show pictures at slightly different sizes, so the sizer first needs a real object to compare with. A bank card is perfect, because every bank card is made exactly the same size.
- Hold your card flat against the card shown on the screen.
- Slide the bar under it until the two are the same height, then tap Done, the sizes match.
- Lay a ring that fits on the circle, and make the circle bigger or smaller until it matches the inside of the ring. If you measured with paper instead, tap My finger and type the length.
Your size then shows for the US, the UK, Europe, Japan and India, all at once.
Getting it right
Fingers are a little smaller in the morning and a little bigger once they warm up, as one jeweller explains. Hot, sticky weather makes them swell slightly, and cold makes them shrink. Blue Nile suggests measuring in the evening, when your fingers are warm, and checking again at another time.
A ring that fits well goes on without effort but catches slightly as it passes the knuckle, as Jewelers Mutual puts it. At the base of your finger, the ring should feel snug without hurting.
If your knuckle is wider than the base
If your knuckle is wider than the base of your finger, measure both places and choose a size in between.
If you fall between two sizes, the bigger one is generally the safer pick. A wide ring (one with a broad band) feels tighter than a thin one, so for a wide ring choose the next size up.
Using a printed sizer at home
The printable sheet shows circles for US sizes 3 to 13, including half sizes. There is also a cut-out paper strip marked in millimetres to loop round your finger.
Some printers make a page slightly smaller or bigger, and then the circles would be wrong. That is why the sheet has the outline of a bank card on it. Print it at full size (100 % in the print settings), then lay a real bank card on the outline. If they match, the circles are right.
Common questions
How large is a size 7 ring?
A US size 7 is a little over two-thirds of an inch across the inside, a very common size for women. In Japan and India the same ring is a size 14.
Is my phone able to measure my ring size?
Yes, once you have matched a bank card to the screen. Your phone remembers the match, so you only need to do it once. The sizer covers every size on the ring size chart, from the smallest to the largest.
How do I measure ring size in centimetres?
Most rulers show millimetres as the small marks between the centimetre numbers. Count to the small mark where your strip ends, and type that number of millimetres into the ring sizer.