Ask a close friend or family member if they happen to know the size. Occasionally, friends may have swapped jewelry in the past or discussed sizes during previous shopping trips. Direct Measurement
If a surprise isn't the priority, the most foolproof method is to measure the finger directly. You can purchase a plastic ring sizer online for a few dollars or visit a jeweler together. When measuring, keep these variables in mind: how do you know what size engagement ring to buy
If you want to keep the proposal a secret, you’ll need to be resourceful. Ask a close friend or family member if
Fingers tend to swell throughout the day. It is best to measure in the evening when the hands are warmest. You can purchase a plastic ring sizer online
The ring must be tight enough not to fall off, but loose enough to slide over the knuckle with slight resistance.
Ultimately, while you want to get as close as possible, don't let the fear of a perfect fit ruin the moment. Most jewelers offer one free resizing after the proposal, ensuring that once the "Yes" is secured, the fit can be perfected.