How to Find Your Partner's Ring Size (and what to do if you can't!)

To most, the thought of proposing to one's partner involves equal parts excitement, suspense and terror. There's a lot to consider, from the location, the atmosphere, keeping it a surprise and of course, the ring. 

Your dreams are filled with the vision of slipping the ring onto your partner's finger with ease, tears running down their cheeks as they shout "I do" (all in slow motion with a gentle breeze flowing through their hair, of course).

Luckily for you, we've comprised a list of a few ways you can sneakily find their ring size without ruining your carefully-planned surprise!


Before you go rummaging around for the tape measure while they sleep, it's important to have an idea of the way rings are measured and the different scales that can be used.

At Class A Jewellers we use AU sizing. Australian sizing uses an alphabetical scale, whereas US sizing is numerical. Both of these scales correspond to the ring's inner diameter and/or circumference. 

Our ring size conversion and measurement chart can be found here.

  • Find a ring they already own 

When choosing a ring to measure, try to find one that they wear on their right ring finger (next to the pinky), as this will likely be the closest fit.

TIP: While the size will be similar, it's important to note that if their dominant hand is their right, their left ring finger may be up to a size smaller.

  •  Ask a close friend or family member

Chances are, their best friend, parents or sibling has bought them a ring in the past and has had to know their size. If not, perhaps they can find out. 

Assign them to a mission. A close friend or family member may be able to discreetly ask or even borrow one of their rings without them knowing to measure!

  • Buy a solo diamond

Another effective and foolproof option is to buy a single diamond or stone to propose with, then come and see us to design the ring together.

This way, you can still surprise your partner with a beautiful diamond, with the added sentimentality of coming up with a design together.

  • Pop the question with a Proposal Ring

If you still want to propose with a ring but don't want to settle on a diamond or design until you have their input, giving them a Proposal Ring can be a great option. You'll be able to surprise your partner with a ring they will keep and treasure forever, and still experience the exciting process of choosing or designing a ring together.

If you have a rough idea, it is always best to choose half a size larger than what you're thinking - it's much easier to downsize a ring than it is to size up. Alternatively (if you think you can get away with it), bring in a few of their rings for us to measure so that we can get a close fit!

If none of these techniques work for you and your only option is to guess, we're still here to help! Once you've chosen a ring you know they'll love, have a chat with us so that we can ensure you that your ring of choice is resizable before proceeding.

After that, it's only a matter of finding the perfect moment to pop that question!