Five Tricks to Figure Out Ring Sizes for Women

By Eustacia Huen

For many, the perfect proposal requires an element of surprise. But how can you keep it a surprise if you don't know her ring size? Since a beautiful engagement ring can easily set you back thousands of dollars, you can't risk guessing. Here are five subtle tricks you can use to figure out ring sizes for women:

1. Copy Her Ring

First and foremost, be prepared to go through her jewelry box or her favorite spot on the dresser for a ring she already owns.

Forget trying on her ring and marking the spot on your finger so the jeweler can do the math. That option leaves lots of room for error. Instead, try tracing the ring—both inside and out—to get a more definitive guide to gauging her ring size. Better yet, Jewelers of America suggests pressing the ring on a soft bar of soap so you get an imprint without having to worry about your drawing skills.

Bear in mind that the engagement ring should go on her left ring finger. Let the jeweler know where the dummy ring is typically worn so he or she can adjust the size accordingly. And if you go for the soap option, make sure you remove all reside before you return the ring to its original spot.

2. Borrow Her Ring

The most foolproof method, of course, is simply to borrow one of your girlfriend's rings and bring it to the jeweler directly. This is the best approach when it comes to accuracy. However, can you do so without leaving a trace? Choose something she doesn't wear too often but you're certain fits (and make sure you know which finger it fits on). And, remember where it's kept so you can return it without anyone noticing once the jeweler is done with the measurements.

3. Get a Ring Sizer

If the thought of drawing or smuggling the ring out of her home feels a bit daunting, get a ring sizer instead. Thankfully, there are plenty of printable ring sizers online to help people determine ring sizes for women. But cover your tracks and remember to delete your viewing history, close relevant windows, and throw away excess printing paper that might show the web page's address.

If this sounds stressful, you can also get a free physical ring sizer from your retailer. Again, just make sure you hide the ring sizer in a safe place.

4. Ask Her Friends and Relatives

This doesn't have to be a one-man job. Ask her friends and close family members (but no blabbermouths!) for advice. Maybe one of them already knows her ring size, while others could help you get the information. For instance, get one of her friends to take her shopping and have her ask your girlfriend to try on different rings for fun. Or, if you're so lucky, someone in her family may be recently engaged and able to naturally slip in the ring size talk without making it sound weird.

5. Measure During Her Sleep

What if she doesn't own a ring? There's no doubt that this is tough if your girlfriend isn't particularly into jewelry. What you need to do is find a time when she's sleeping very soundly, wrap a string around her ring finger, and measure accordingly. It may be tempting to double- or triple-check the measurements, but be sure to do it gently so you don't wake her up.

At the end of the day, there's always the need for a contingency plan. According to The Knot, when in doubt, you should get a larger ring size, since it's easier to resize a ring smaller than it is to go bigger.