Working out your partner’s ring size without asking outright can be a challenge. You want to keep the surprise, but you don’t want to get it completely wrong. The good news? There are some realistic and believable ways to find out their ring size without raising suspicion.
Here are genuinely doable ideas to help you get it right - plus a few things to keep in mind about resizing and jewellery insurance.
1. Ask a friend (but make it casual)
This is one of the most reliable routes - but it needs to feel organic. If your partner has a close friend who’s engaged or into jewellery, ask them to casually bring up the topic:
- “I was helping my sister pick out rings, what size are you?”
- “Try on my ring, see how it looks on your finger”
- “We should get matching rings from that boutique shop – what size do you take?”
The key is keeping it natural and unforced. Done right, it won’t raise eyebrows.
2. Look at a ring they already wear
If your partner wears rings - especially on their ring or middle fingers - try to borrow one discreetly or examine it closely. Take a photo of it on a ruler, trace around it on paper, or press it into some blu-tack or soap to get an accurate imprint.
Just make sure you know:
- Which hand and finger it came from.
- Whether it’s a ring they genuinely wear on that finger, rather than something they just slip on occasionally.
If you know the size of one finger but need to estimate another, here’s a helpful guide:
- From the little finger to thumb, each finger is typically about one full size larger than the one before it.
- And the same finger on your dominant hand tends to be around half a size bigger than on your non-dominant hand.
This means ring sizes on a dominant hand are generally larger overall. So, when borrowing a ring to guess their engagement ring size, try to borrow one from their left hand, ideally the ring finger. If you borrow a ring from the right hand (especially if they’re right-handed), it may give you a slightly larger size than needed, which can make it harder to get a perfect fit.
Jewellers can work with these clues and adjust accordingly - just let them know what you borrowed and from where.
3. Use a ring multi-sizer (or string) while they sleep
This one’s bold - but surprisingly doable if your partner is a deep sleeper. Gently:
- Wrap a piece of thin string, floss, or paper strip around their ring finger.
- Mark where it overlaps and measure it against a sizing chart.
- Or use a plastic ring multi-sizer, which you can order online. These are quiet, soft, and accurate.
Bonus tips:
- Measure at room temperature - fingers are smaller when cold.
- Don’t pull too tightly or the size will come out wrong.
4. Take them shopping “for someone else”
Next time you’re in town, pretend you’re looking for a gift for your sister, mum, or friend. Ask your partner to try on a few rings to “get an idea of sizing”. You can act distracted while mentally noting what fits them best.
Bonus tip: take them somewhere you wouldn’t normally go to avoid questions later.
5. Notice how their rings fit you
If they’ve left a ring lying around, try it on your own fingers and note where it fits. A jeweller can often estimate their size based on how far it fits down your little or ring finger. You can even draw a small line on your finger to mark how far it went.
Just don’t forget which ring it was - or leave any evidence behind.
6. Use a ring sizing app
There are free apps where you can place a ring on your phone screen and match it to standard sizes. If you’ve managed to borrow a ring or trace it, this is a very handy and discreet option.
You’ll find printable ring size guides online too - just make sure you print them to scale.
7. Involve a mum, sister, or cousin
If your partner is close to a family member, they might already know the size - or be able to find out without it seeming strange. A mum might even have a childhood ring tucked away that still fits.
Just be sure to ask someone who won’t accidentally let the secret slip.
What if you get the size wrong?
It’s totally normal. Even if you do your best, fingers change size depending on the time of day, temperature, or even how hydrated we are.
The good news:
- Most jewellers expect to do at least one resize.
- Making a band smaller is typically easier, so err on the side of slightly bigger.
- Simple band styles are easier to adjust than intricate eternity rings.
When buying, ask your jeweller about their resizing policy and turnaround time - especially if you’re planning a holiday proposal or working to a tight deadline.
Don’t forget jewellery insurance
Once you’ve found the perfect ring, don’t stop there - protect it with suitable jewellery insurance.
Here’s why:
- Home insurance might not cover it fully. Many have low single-item limits that won’t stretch to an expensive diamond ring or bespoke piece. (Is jewellery covered by home insurance policies? discusses this in more depth).
- Accidents happen - dedicated ring insurance cover gives peace of mind.
- Worldwide protection. If you’re proposing abroad, you’ll want to be sure your insurance travels with you. (Our blog: Travel guide for taking your jewellery abroad explains this in more detail).
A specialist provider like us here at Assetsure offer flexible cover, including accidental loss, theft, and damage* - ideal for protecting sentimental and high-value pieces.
Getting the right ring size
Finding out their ring size without spoiling the surprise doesn’t need to be a covert operation - it just takes a little planning and creativity. From subtle chats and helpful friends to quiet measurements while they sleep, there are plenty of ways to pull it off.
And if the ring’s a fraction off? That’s nothing a quick resize typically can’t fix.
Just don’t forget that once it’s on their finger, it’s not just a beautiful symbol - it’s a valuable item worth protecting. Jewellery insurance gives you confidence that no matter what happens, your special moment (and your investment) is secure.
*Subject to the policy terms and conditions being met – please see point 5 under our blog: Top 6 mistakes people make with their jewellery insurance or call us on 0208 0033 190 for more information.
