How to Measure Your Ring Size at Home
You can measure your ring size at home with a strip of paper and a ruler: wrap it around the base of your finger, mark where it overlaps, and measure that length in millimetres to get your circumference. Measure late in the day when your fingers are at their largest, and take the reading three times, because finger size changes by up to half a size between morning and evening.
Updated 2026-09-12
Measuring from a ring you already own
If you have a ring that fits the same finger, this is the more reliable method. Measure the inside diameter across the widest point, edge to edge, in millimetres.
An inside diameter of about 17.3mm corresponds to a US 7. Multiply the diameter by 3.14 if you want the circumference to compare against the paper method. Measure the inside of the band, not the outside, and do not include the thickness of the metal.
Australian and US sizing
Australia and the UK use letters, from A upward. The United States uses numbers. The two scales are not interchangeable, and the same ring carries a different label in each.
As a reference: US 5 is Australian J, US 6 is L, US 7 is N, US 8 is P, US 9 is R and US 10 is T. Half sizes exist in both systems. If a seller quotes only one scale, convert before ordering rather than guessing.
What throws a measurement off
Temperature is the big one. Fingers shrink in the cold and swell in heat and humidity, so a measurement taken on a cold morning can be a full size smaller than the truth. Measure when you are warm and at rest, ideally in the evening.
Band width matters too. A wide band sits tighter than a narrow one at the same nominal size, so for a band over about 6mm, consider going up a half size. Knuckles that are noticeably larger than the base of the finger need a size that clears the knuckle, even if it leaves the ring a little loose below it.
Measure your ring size with paper
Cut a strip of paper
Cut a strip about 5mm wide and 100mm long. Paper works better than string, which stretches and gives a reading that is too large.
Wrap it around your finger
Wrap the strip around the base of the finger you will wear the ring on. It should sit snug but slide over the knuckle without forcing.
Mark the overlap
Mark the exact point where the end of the strip meets the rest of it, then unwrap the paper without stretching it.
Measure in millimetres
Measure from the end of the strip to your mark with a ruler. That length is your finger circumference in millimetres.
Check it against a size chart
Convert the circumference to a size. A circumference of about 54mm is a US 7 or an Australian N. Repeat the measurement three times and take the largest reading.
Common questions
- What is the most common ring size?
- For women the most commonly ordered sizes are US 6 to 7, roughly Australian L to N. For men they are US 9 to 11, roughly Australian R to V. These are averages and not a substitute for measuring.
- Should I measure in the morning or the evening?
- Evening. Fingers are at their smallest first thing in the morning and swell through the day. Sizing to a morning measurement usually produces a ring that feels tight by dinner.
- Can string be used instead of paper?
- It can, but it is less accurate. String stretches under tension and compresses the finger, which typically produces a reading half a size too large. A paper strip is stiffer and more repeatable.