How to Find Their Ring Size Without Asking

Planning a surprise proposal means getting the ring size right without asking. The good news: there are several reliable ways to find it quietly, and if you are slightly off, a ring can be exchanged for another size. Here is how to do it, from the most accurate method to the last resort.

1. Borrow a ring they already wear

The most accurate method is to measure a ring that fits the finger the engagement ring will go on, usually the fourth finger of the left hand. If they only wear rings on other fingers, a ring from the same finger on the other hand is the next best thing.

Measure the inside diameter of the ring in millimeters, straight across the widest point inside the band, and compare it with the chart in our ring size guide. If you cannot keep the ring long enough to measure, do one of these instead:

• Place it on a sheet of paper and trace carefully around the inside of the band with a fine pen.
• Press it gently into a bar of soap or a piece of modeling clay to leave a clean impression.
• Slide it as far as it will go onto a marker or a tapered bottle neck and mark the spot.

Any of these gives you a measurement to bring back to the chart later.

2. Ask someone close to them

A best friend, sibling or parent may already know the size, or can find out casually: a shopping trip that includes trying on rings, or a conversation about a ring they are buying for themselves. Choose someone who can keep a secret.

3. Look for clues

Check jewelry boxes for receipts or old ring boxes, which sometimes note the size. Rings bought online often show the size in the order confirmation email or account history.

4. Compare with your own hand

If you have tried their ring on before, remember where it stopped on your own fingers. A ring that fits your little finger, for example, gives you a rough starting point. This is the least precise method, so use it only to narrow things down.

Tips for an accurate size

• Fingers change during the day. They swell in the warmth and in the evening and shrink in the cold, so a ring measured late in the day is the most reliable.
• The dominant hand is often slightly larger. A ring from the right hand may run a little big for the left.
• Wide bands fit more snugly than thin ones of the same size.
• When in doubt, size up. A slightly large ring still slides on for the proposal. A ring that is too small will not go over the knuckle.

If the size is not quite right

Women's rings come in US sizes 5 to 9 and men's rings in US 8 to 12. Size exchanges are free on all rings: email voice@carissie.com with your order number and the size you need, and we will send instructions. Every ring arrives in a Carissie gift box, ready for the moment.

Once you have the size, browse our moissanite engagement rings, or start with our guide to engagement ring shapes.