How to find a ring size without them knowing
Planning a surprise? Here are five discreet ways to get the size right — and the safest size to pick if you simply have to guess.
- Borrow a ring they already wear. Take a ring from the correct hand (rings are usually worn on the ring finger) while they’re not wearing it, and measure its inner diameter in millimetres.
- Trace the inside. If you can’t take the ring, trace around the inside on paper and measure the circle’s diameter, or press it into a bar of soap to capture the size.
- Compare to your own finger. Slide their ring onto your own finger and mark where it stops — then measure your finger at that mark later.
- Ask a friend or family member. Someone close may already know the size, or can casually ask. A sibling or best friend is your safest source.
- Choose a resizable style. When in doubt, buy a resizable ring near the average (US 6 for women, US 9 for men) and resize after the proposal.
If you have to guess
The average is about US 6–6½ for women and US 9–10 for men — see the full average ring size data. Choose a resizable metal (gold, silver, platinum), and avoid full-eternity or tungsten styles that can’t be resized.
Frequently asked questions
How can I find out her ring size without her knowing?
Borrow a ring she wears on her ring finger and measure its inner diameter, or trace the inside on paper. You can also ask a close friend or family member, or slip her ring onto your own finger and mark where it stops. As a fallback, choose a resizable style near US 6.
What is the safest ring size to guess for a proposal?
US 6 to 6½ for women and US 9 to 10 for men are the most common sizes. Pick a resizable style and have it adjusted after the proposal if needed.
How do I measure a borrowed ring?
Measure the inner diameter across the middle in millimetres and match it on our chart, or use the converter’s “Diameter (mm)” option. Even a paper tracing of the inside works.