The Ultimate Ring Sizing Masterclass: Getting it Right (Without Spoiling the Surprise)

The proposal is meant to be one of the most magical moments of your life. But for many, the stress of getting the ring size “just right” turns the lead-up into a high-stakes guessing game.

At Moissanite Shine, we have helped thousands of partners navigate this exact challenge. The truth? Getting the right size is easier than you think—if you have the right strategy. You don’t need a degree in jewelry design; you just need a little bit of detective work. And when you’re ready to choose the ring itself, our Moissanite Engagement Rings collection is the perfect place to start.

1. The “Jewelry Box Raid” (The Borrowing Method)

The most accurate way to get her size is to “borrow” a ring she already wears on her ring finger (on either hand).

• The Trick: Take one of her rings to a local jeweler or use our printable Ring Size Guide—make sure you print it to scale!
• The Pro Tip: If you can’t take the ring out of the house, trace the inner circle of the ring on a piece of paper with a sharp pencil. That inner circle is the most important measurement.

2. The “Partner-in-Crime” (The Most Reliable Method)

If you aren’t living together, or if you are worried about getting caught, don’t play the detective yourself. Recruit a “Partner-in-Crime.”

• Who to ask: Her best friend, her sister, or her mother. They are often the ones who have gone shopping with her or who know her jewelry habits inside and out.
• The Bonus: They might even know her ring size off the top of their heads because she has mentioned it while admiring jewelry in the past.

3. The “Low-Tech” Sizer (When in Doubt)

If you can’t borrow a ring and don’t have a reliable “Partner-in-Crime,” we recommend ordering a Plastic Ring Sizer.

• Why it works: It’s a simple, inexpensive tool that looks like a zip-tie.
• How to use it: You can subtly leave it on a vanity or ask her to “help you test” something for a friend’s wedding. It’s a harmless way to get the exact measurement without raising suspicion.

For a full visual guide to measuring at home, visit our dedicated Ring Size Guide & Jewelry Care Tips page.

The “Size” Commandments: Don’t Ignore These!

Before you measure, remember these three rules:

• Temperature Matters: Fingers swell in the heat and shrink in the cold. Never measure her finger when she is hot (after a workout or a hot day) or freezing cold. Aim for “room temperature” for the most accurate result.
• The Knuckle Trap: The ring needs to fit over the knuckle, not just the base of the finger. If she has prominent knuckles, the ring may need to be slightly larger than the base measurement.
• The “Dominant” Difference: Fingers on the dominant hand (the one she writes with) are usually slightly larger than the fingers on the non-dominant hand. Keep this in mind if you are measuring based on a ring from her other hand.

What if You Get it Wrong? (The “Safety Net”)

Here is the secret that no one tells you: Getting the size slightly wrong is perfectly normal.

Most jewelry designs can be resized by a professional jeweler. At Moissanite Shine, we work with you to ensure the fit is perfect. If you are ordering a custom piece, we will guide you through the sizing process step-by-step. And if you receive the ring and it’s a tiny bit off, don’t panic—we have a process to help you get it adjusted.

Every piece we sell is also backed by our Lifetime Gemstone Warranty and our Lifetime Upgrade Program—so your ring can grow and evolve with you over time.

Planning a surprise proposal? Read our Smart Engagement Guide to make sure every detail—including the budget—is perfectly planned.

Need a Second Opinion?

If you are still nervous about the size, reach out to us before you order. Visit our Frequently Asked Questions page for instant answers, or Contact Us directly—tell us about the ring design you are considering and give us any information you have about her size (even a guess!). We can often look at the specific design (thicker bands vs. thinner bands) and give you expert advice on whether to size up or down.

Want to go one step further? Request a Custom Design and we’ll guide you through every detail, including sizing, from start to finish.

Stop guessing and start planning. Browse our Moissanite Engagement Rings and let’s get that ring perfectly sized—so you can focus on the question you’re about to ask.

Written by the customer care team at Moissanite Shine. Precision in every fit.