How to measure your ring size at home

All you need is a strip of paper and a ruler. Here is how to measure accurately, and how the result maps to US, UK and EU ring sizes.

Updated 9 October 2026 · 6 min read

Method 1: measure your finger with paper or string

1. Cut a strip of paper about 5 mm wide and 10 cm long. Paper is better than string because it does not stretch and is easier to mark.
2. Wrap it around the base of the finger where the ring will sit. It should be snug but not tight: you should be able to slide it over the knuckle with a little effort.
3. Mark the point where the paper overlaps with a fine pen.
4. Lay the strip flat against a ruler and measure from the end to the mark in millimetres. That is the circumference.
5. Repeat two more times and use the average. Half a US size is only about 1.3 mm of circumference, so care pays off.

Type the result into the ring size converter to get your size in US, UK, EU and Japanese systems at once.

Method 2: measure a ring that already fits

1. Pick a ring that fits the same finger on the same hand comfortably.
2. Place it on a ruler and measure the inside diameter, edge to edge across the widest point, in millimetres. Do not include the metal itself.
3. Look up the diameter in the table, or enter it in the converter with "Inside diameter" selected.

This is usually more accurate than the paper method, because a ring already accounts for the knuckle. A ruler is only precise to about half a millimetre, though, and 0.4 mm of diameter is a full half size. If you have a caliper, use it.

Method 3: a printable ring sizer

Many jewellers offer a printable sizer. It only works if it prints at exactly 100% scale: in the print dialog, choose "Actual size" or "100%" rather than "Fit to page", then measure the reference line on the printout with a ruler before you trust it. A sizer printed just 3% too small is off by more than half a size.

International ring size chart

The table follows the common US scale and the ISO 8653 standard, where the EU size is the inside circumference in millimetres, rounded. UK and Australian letters are the nearest match; UK sizes go up in half letters, so a US size and a UK letter are rarely an exact match.

Japanese sizes, and the sizes used in China and India, are also on whole-number scales, but published conversion charts disagree with each other by about one size. The converter shows a Japanese size as a guide; for an important purchase, check the jeweller's own chart.

Tips for getting it right first time

• Measure at the end of the day. Fingers are often slightly larger in the evening and in warm weather, and smaller when cold. Avoid measuring straight after exercise or a hot shower.
• Check the knuckle. If your knuckle is much wider than the base of the finger, measure both and choose a size between the two, closer to the knuckle. The ring has to get over it.
• Wide bands fit tighter. A band wider than about 6 mm touches more skin and feels snugger. Many jewellers suggest going up a quarter to half a size for wide bands; ask the seller.
• Each hand is different. Your dominant hand is often a little larger. Measure the exact finger the ring is for.
• Between two sizes, go up. A slightly loose ring can be fixed with a sizing insert; a tight one has to be resized.
• Brands differ. Two jewellers can be half a size apart for the same nominal size. If the brand publishes its own chart, use it.

If you get it wrong: which rings can be resized

Plain bands in gold, silver or platinum can usually be made a size or two bigger or smaller by a jeweller. Some rings are hard or impossible to resize: tungsten, titanium and ceramic bands, rings with stones set all the way around (full eternity rings), and rings with engraving or patterns around the whole band. For those, measuring carefully before you order matters most. Policies vary, so check the seller's resizing and exchange terms.

Buying a ring as a surprise

If you cannot measure the finger, borrow a ring the person wears on the same finger and measure its inside diameter as in method 2, or press it into a bar of soap or modelling clay and measure the impression. Average women's ring sizes are often quoted around US 6–7 and men's around US 9–10, but these are only rough starting points; many jewellers offer free resizing within a period, so check before you buy.

Frequently asked questions