What ring size should I buy for a surprise gift?

ZKZ Editorial TeamMain answer · Product & gemmology desk

Find out the size from a ring the person already wears on the same finger, or buy a style that can be resized and agree an exchange or resize before you order. If you can only guess, a slightly larger size is usually easier to live with than one that does not go over the knuckle, but a wrong guess is common, so plan for it.

Ways to find the size without asking

1. Borrow a ring. Take a ring they wear on the same finger, ideally the same hand, for a short time and either trace the inside of the band on paper or press it into a block of soft material. Measure the inside diameter in millimetres and match it with the size chart of the shop.
2. Use a photograph. Ask the jeweller to compare a photo of a ring on their finger with a known ring, which only gives a rough range.
3. Ask someone who knows. A relative or friend may know the size from a previous purchase.
4. Use a ring-sizer tool while the person is asleep or distracted. It is fiddly and it may not be accurate, because fingers swell and vary in the day.

Be careful with sizing standards

Fact There is no single worldwide ring-size scale. US, UK, European and Asian charts differ, and some shops list the inside diameter or circumference instead.

Our advice Always match your measurement to the chart the seller uses, in millimetres if available, and check whether half sizes are offered. Confirm the size in writing in your order.

If you are unsure

• Choose a ring that can be resized. Plain bands and solitaires are easy to adjust. Rings with stones all the way around, wide bands and some unusual shapes are difficult or impossible to resize, so avoid them if you are guessing.
• Pick a different finger if the ring is not a promise or wedding ring. A ring on the right hand or the middle finger gives you wider tolerance.
• Agree a resize or exchange before you pay. Ask whether the first resize is free, how long it takes and whether a wrong size can be exchanged. Keep the receipt and the packaging.
• Size by finger and season. Fingers can be larger in heat or in the evening, so a measurement taken at one time of day may not be right at another.

Uncertain We cannot tell you how much of a size difference a given ring allows. It depends on the width of the band and the person's knuckle. When in doubt, ask the seller and ask the person afterwards, with a plan to exchange.

Related reading: How to Find Your Ring Size at Home (Free Printable Method) · Resizing a Sterling Silver Ring: What Is Possible

Sources

No external standard governs this question, so this answer is editorial advice from the ZKZ team and is labelled that way.

Fact = stated by the cited source. Our advice = editorial recommendation. Uncertain / it depends = limits of what can be said in general.