Tips and Tricks

Sizing Up the Situation: Picking the Right Ring Size

You’ve loved them at their best (hello sleeping angel). You’ve seen them at their worst (hello outfit tantrums). You’ve accepted the fact that they will never leave the bathroom countertop clear of beauty products (apparently these are all super important and cannot be kept in the cabinet, which was specifically made for such purposes, but I digress).

You’ve decided that you cannot possibly live without them. You’re in this for the long haul. It’s engagement ring time!!!!!!

This is where we come in, because let’s face it, you haven’t got clue what you are doing. #TruthBomb
You might know your budget. You might know that she (or he!) prefers white gold. You might even know that they love princess cut diamonds (don’t we all). This is all great news, but do you know the correct ring size for that beautiful little finger? Of course you don’t, because otherwise you wouldn’t be reading this article. I mean, unless you seriously love our funny and informative posts and are reading them simply for the sheer joy of it (go outside and stop being weird).

The problem is that unlike shoes size, the correct size of our ring finger isn’t exactly something most of us know off the top of our heads. Now before you start having a mini panic attack, know that Rare Carat is here to help you navigate this tricky situation.

First of all, what is your ring size? Your ring size is the approximate diameter of the inside of a ring that will comfortably fit on your ring finger. Your ring finger is the third finger on your left hand (the one before the pinky). Here is a handy diagram for those of you that are more visually inclined:

Difference between ring circumference & diameter

The aim is to find out this diameter business and then locate the corresponding ring size on a ring size chart such as this:

Ring Size Chart

Seems easy, but just like life (and also baking), sometimes the things that seem straightforward are the things that end up a hot mess.

Because we don’t want you to fail, we’ve outlined a few little tricks to help you figure out the appropriate ring size for that ring finger, but first we want to run through some general info that you should be aware of. These will hopefully help you avoid disaster, and we are calling them our ‘Forget Me (K)nots’ because we cannot help ourselves. Forget me nots as in ‘don’t forget’, but also knots as in ‘tying the knot’! Get it? Ugh, forget it. We’re wasted on you.


  • Don’t get confused between diameter and circumference when getting your measure on; the diameter of a ring is the length of the inside of the ring (i.e. the size of the finger), whereas the circumference is the length of the entire band. You want the diameter.
  • The fingers on your dominant hand will be a little larger (the one you write/pick up wine glass with). So what fits on the third finger of the right hand (if you are right handed), might be too big on the left. The opposite applies if you are left handed.
  • Finger size can change depending on the season or even the time of day! Hot weather will mean swollen fingers, while cold weather means shrunken fingers. We also tend to have puffier fingers in the morning (especially if we’ve had a few martinis the night before). Keep that in mind when taking you measurements… what fits now may be too big/too small in a few months’ time.
  • Don’t just blindly guess their ring size. This can go horribly wrong. Play it safe and try to figure it out, at least roughly.
  • Don’t try to figure out the correct size using a piece of string or paper wrapped around their finger. It’s not an accurate measurement and it ain’t cute.
  • When in doubt, always go for the ring that's a larger size rather than too small. Have you ever tried on a piece of clothing that you really wanted, only to find out it’s too small? Now imagine that with an engagement ring. There are always temporary ring guards to help the ring from slipping off if it’s too big.
  • Resizing for the perfect fit can usually be done up to two sizes up/down on plain bands, BUT is far trickier with a ring that has diamonds in the setting (i.e. pavé set diamond ring). Avoid going for a infinity pavé set ring or eternity ring (diamonds the whole way around the band), as this way you avoid resizing issues in the future.

Now that we ‘ve covered the basics, let’s get into some kinda sneaky and uber fun ways to figure out that right ring size without ruining the big surprise!


This one is easy peasy and might also make you feel a little like James Bond. All you’ll need is a piece of paper, a pencil, some quick reflexes and a good poker face. Wait until the unsuspecting target is in another room binging on Netflix. Sneakily sneak into their jewelry box and take out a ring you know fits them (you’ve seen it on their finger before). Maybe it's a promise ring you've already given them, maybe it's a tacky cocktail ring they just can't quit.

Pop the ring on the piece of paper you have obviously brought with you, and trace the inside of the ring with the pencil. Take two or three traces just in case you mess one up. Now all you do is get the hell outta there and use a printable ring sizer/ring size guide or your local jeweler to calculate the size based on your drawing.

For this method to work though, you do need to know what finger she/he wears this particular ring on. It’s no good if you pick a thumb ring and then take the measurement as if it was her/his middle finger. That ring gonna slip off like a drunken Irish man at a house party. If you are not sure which finger the ring usually lives on, get on social media and get to stalking. You’ll most likely see them wearing it, and be reminded of how lovely they are at the same time. Winner.

Another variation of the trace method ditches the paper and only uses a pen to trace the outline of the ring around your own pinky or ring finger. Simply slip it on and trace just below (not above) where the ring is snugly resting on your own finger. If you are a lady measuring for a man, throw that ring on your thumb. As before, use a printable ring size chart or your local jeweler to figure out the ring size. And remember, it’s always better to go a little larger in size than risk the ring being to small.


The borrowing method takes the tracing method to the next level. The basic premise is that you find a ring that they wear just as before, but this time instead of messing about with paper and pens, you just take the damn ring and run.

Once you have the ring safely out of house, take it to a jewelry store and have them size it for you. Alternatively, you can print off a pdf ring size chart and simply place the ring on each circle until you can figure out the corresponding size. Just as before, you need to know what finger this ring usually sits on, so that you can work from there to figure out the ring finger size. The general rule of thumb (YES. I WENT THERE. I REGRET NOTHING), is that you go one size down from middle to ring finger - so if the stolen ring is worn on their middle finger and that measures as a 7.5 size, then it’s a fairly safe bet to think that a 6.5 size engagement ring will fit on the ring finger next to it. And don’t forget that a ring that fits perfectly on the right-hand ring finger may be the wrong size for the left ring finger (provided the wearer is right handed of course).

There is slightly more risk involved in this particular method, especially if this ring is something they wear often. Try to get your business done in fairly quick time here, just in case she/he finds the ring gone and loses their mind.


If Elmer Fudd were here, this would be his favorite method. Not only are we pronouncing ‘ring’ like ‘wing’ which is always adorable, but we’re also enlisting the help of some loved ones! If borrowing one of their rings is just not an option, this is certainly another way to go.

Asking a sister or best friend is always a good bet here, as chances are that there has been at least some chatter about ‘the ring’. A BFF or sister is likely to know what ring size is needed, or at the very least will be in a position to find out very easily for you. They might go shopping and try on rings together (and report back to you immediately), or indeed offer your unsuspecting target a chance to try on their ring so they can gauge if it’s the right fit.

You could even plan a night out with friends who have recently gotten engaged, and making sure that the brand-new engagement ring is tried on by your own unsuspecting target. Watch carefully (or get someone else to) in order to see if the ring is too big or too small. Make sure you ask the newly engaged couple what size the ring was, and this will give you a good idea of what size to get based on how well it slipped on to her finger. She’ll never suspect a thing!

A word of warning here my friends. You must be very careful with this particular tactic, because for this to work you need to have some peeps who are willing to play ball, but also willing to keep their mouths firmly shut about the whole affair. The last thing you need is a blabbermouth ruining your big surprise, by behaving like this.


Ask her yourself.

No, seriously! If you guys have been talking about the big ‘M’ for a while now, or she’s been dropping mad hints of late - such as pointing out other girl’s rings or screaming “I WANT A DIAMOND!” in your face while you’re asleep on the couch – then we think it’s cool to suggest that she give you her ring size so that when the time comes, everything is truly perfect. It won’t ruin the surprise when you eventually drop down on one knee, and I know this because I accidently found my ring box MONTHS before my now husband actually got around to asking me (don’t worry, I didn’t open it). This is 100% a true story, and made for some preeeeetty hilarious situations where I DEFINITELY thought he was going to ask and he absolutely didn’t.

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