Method 1: Measure a Ring She Wears Now
If you’re wanting to have a surprise proposal, secretly “borrow” and measure a ring that fits her left-hand ring finger (or the finger you intend her to use). Tread carefully. You don’t want her to find out, and you definitely don’t want to accidentally lose the ring! Depending on how much time you’ll have with the ring before she notices it’s gone, here are a few tactics to consider to find her ring size:
1. Take it to a jeweler. If you have a few hours, take the ring to a local jeweler to size it professionally. While this takes some time, it’s also the most accurate way to find her ring size.
2. Invest in a ring mandrel. To quickly and accurately measure the ring yourself, purchasing or borrowing a ring mandrel (also called a ‘ring sizer’) is a reliable and accurate option. Slide the ring down the mandrel. The line where the ring stops indicates the ring size.
3. Use the ring sizing chart. Be sure to print it ahead of time and use a ruler to double-check that it is precisely to scale. Move the ring from circle to circle until you find the best match for the ring’s inner diameter. If the ring lands between two sizes, always choose the larger one.
4. Trace it. Carefully trace the inside and outside of the ring on a piece of paper. Repeat several times for added accuracy. Take the paper to a jeweler for a size estimate.
5. Try it on yourself. If pressed for time, try the ring on your own fingers and see if one of them fits well. If it does, you can measure that finger later to figure out the size on your own time.