How To Measure Your Partner’s Ring Size (Without Them Knowing)

By Charlie Colville

4 weeks ago

Planning a (top secret) proposal? We've got you covered


It’s officially cuffing season. And if a proposal is on the cards, chances are you’re looking for the perfect ring. But first, you need to know the right size – preferably, without cluing in your partner on your plans. That brings us to the big dilemma: how to measure your partner’s ring size, in secret. ‘We get a lot of questions regarding ring sizes,’ says Ayça Özbank Taskan, founder and creative of MARA PARIS. ‘Determining the right ring size can be a tricky task, especially considering the variations in sizing systems across different countries.

‘However, you can find a better fit for your partner with a few tips and tricks,’ she continues. ‘Winter is the romantic time of year, and we always see an uplift in people looking to buy engagement rings. We’ve curated some top tips to help those looking to get the perfect fit.’

How To Measure Your Partner’s Ring Size

‘The best way to ensure accurate sizing is to visit a local jeweller, but when wanting to surprise your partner, this is an impossible task,’ begins Ayça. ‘The best way to measure effectively is to take a ring your partner already wears to compare. If you’re worried they’ll notice it’s gone missing, wait until they’re out, and then measure the inner diameter using a ruler. Simply measure from one edge to the opposite edge which represents the ring’s inner diameter, then use the chart below to find the correct corresponding ring size. This method is discreet and ideal for gifting as well.’

What Ring Sizes Are There?

In the UK, ring sizes go up in letters, and measure the inner diameter of the ring in millimetres. We’ve listed some of the most common ring sizes below so you can get an idea:

  • UK Size I: 15.28mm
  • UK Size J-K: 15.92mm
  • UK Size L1⁄2: 16.55mm
  • UK Size N: 17.19mm
  • UK Size O3⁄4: 17.83mm
  • UK Size Q 1⁄2: 18.46mm
  • UK Size S: 19.1mm
  • UK Size T1⁄2: 19.74mm
  • UK Size V: 20.37mm

Other Things To Consider

Finding the ring size is just the first step – but not the easiest one. Below, the MARA PARIS team has rounded up a few tips to get you started:

Personal Preference

It’s important to remember when choosing a ring that everyone has a personal preference, and knowing your partner well will be a key factor in making sure you buy them the perfect ring. However, if you’re unsure, a simple tip is to look at the current rings in their collection. From this, you’ll be able to see if they opt for thinner or thicker widths, and looking at the placement of rings on their hands will give away if they prefer a snug fit or looser feel, which you can consider when choosing.

Finger Variation

A great way to get someone’s ring measurement is to take a ring from their current collection to compare at a jeweller’s. However, it’s important to remember that every finger is unique, and sizing may be different from one finger to another. The dominant hand may also have a slightly larger size due to increased muscle tone, so make sure you take a ring they’d wear on their engagement ring if this is the route you decide to take.

Ring Design

One of the hardest things to consider is the design of the ring itself. If your partner prefers a thicker band, this may require a larger size for comfort, whereas a typical thin band ring, which is popular, should fit their usual ring size, so think about this when picking sizing.

Seasonal Changes

Finger size can fluctuate with changes in temperature and hydration levels, which is important to remember in the colder months. If your partner complains that their rings don’t seem to fit with the change in weather, bear this in mind when you come to design or choose your ring.

Ask A Family Member Or Friend

If you’re struggling to subtly find out your partner’s ring size, the best way could be to speak to a family member or friend who may have bought them a ring as a gift before. Similarly, they may be aware that they have a similar ring size and you could use them as a base to compare.

Playfully Ask

Sometimes, the easiest way to find out is to simply ask. You can jokingly say it to your partner as though you were thinking of buying a ring or position it as a future question you want to be aware of so that you can make sure you get it right when the time comes.

Go With The Average Size

If you feel you’ve exhausted options and are still having difficulty deciding, go for the average ring size. Most jewellers will understand that measurements can’t always be perfect, and you’ll be able to swap or resize based on your ring choice.

Featured image: Tony Litvyak, Unsplash