How to Measure Ring Size at Home
You can measure your ring size at home three ways: print a true-scale sizer and wrap it, wrap a strip of paper or string and measure it against a ruler, or measure the inside of a ring that already fits. Each one comes down to the same number, the inside circumference in millimeters.
Method 1: a print-to-scale sizer (most accurate)
This is the closest you get to a jeweler's sizing tool at home. Print the ring sizer at 100% scale. Before you measure, check the print: the 50 mm line on the sheet should read 50 mm under a ruler, or a bank card should fill the printed box exactly. That check matters, because most printers shrink a page a few percent by default, and a few percent is most of a ring size.
Once the scale checks out, cut the strip, wrap it snug around the base of your finger with the numbers facing out, thread the end through the slot, and read the size where the slot edge lands. Snug, not tight. You want the ring to clear your knuckle, so do not pull it down hard.
Method 2: string and a ruler
No printer? Use a thin strip of paper or a length of string. Wrap it once around the base of the finger, snug, and mark the spot where it meets itself. Unwrap it, lay it flat against a ruler, and read the length in millimeters. That number is your inside circumference.
To turn it into a size, match the millimeters to the circumference column on the ring size chart, or type it into the converter on the sizer page. One caution: string stretches and paper slides, so measure three times and take the reading you get most often.
Method 3: measure a ring you already own
If you have a ring that fits the right finger, you can skip your finger entirely. Lay a ruler across the inside of the ring and read the widest gap in millimeters. That is the inside diameter. Match it to the diameter column on the chart, or lay the ring over the circles on the printable sizer and find the one whose outer line meets the ring's inside edge.
This is the method to use for a surprise. More on that in how to find their ring size secretly.
Get a true reading
- Measure in the late afternoon. Fingers are smallest in the morning and after cold, largest later in the day.
- Warm your hands first. Cold fingers read a half size or more too small.
- Measure the finger you will actually wear the ring on. The two hands differ, and so do fingers.
- If the band is wide, add a quarter to a half size. A wide ring needs more room to pass the knuckle.
When you have a number, the printable sizer and the size chart will confirm it in both millimeters and US, UK, and EU sizes.
Frequently asked questions
What is the most accurate way to measure ring size at home?
A true-scale printed sizer is the most reliable, because it reads the size directly instead of asking you to convert. The string method works too, but it adds a step where small errors creep in. Either way, measure two or three times and measure when your hands are warm.
How do I measure ring size with string or paper?
Wrap a thin strip of paper or a piece of string around the base of your finger, mark where it overlaps, then lay it flat against a ruler and read the length in millimeters. That length is your inside circumference. Match it to a US size on the chart, or type it into the converter.
How do I measure a ring I already own?
Lay a ruler across the inside of the ring and read the widest gap in millimeters. That is the inside diameter. Match it to the chart, or drop a ring over the circles on the printable sizer until one lines up with the inside edge.
Why does my ring size keep changing?
Fingers swell and shrink with heat, salt, and time of day. They are smallest when you are cold or first wake up, and largest in the late afternoon and in warm weather. Measure in the afternoon when your hands are at a normal temperature for the truest size.
Should I size up or down if I am between sizes?
Size up, especially for a wide band. A ring has to clear the knuckle, which is usually wider than the base of the finger, so a touch of room is better than a ring that will not go on.