If you are planning to propose this Christmas and you have no idea what ring size she wears, you are in good company. It is the single most common question we get in December, and the honest answer is reassuring: the size is the easiest part of the whole thing to fix.
Here is how to handle it, in the order that actually matters.
First, the date that decides everything
Every piece we make is made to order, so the calendar matters more than anything else on this page. We need about 4 business days to make and dispatch a ring, plus about 4 business days in transit. That means the last safe order date for delivery before Christmas is Monday 14 December 2026.
Order after that and we will still make the ring and send it, but it is likely to arrive after Christmas Day. If you are reading this in the week of the 14th, place the order first and work out the size afterwards. The size can be changed. The date cannot.
Second, stop trying to measure her finger
Most people's instinct is to wrap a piece of string or a strip of paper around her finger while she sleeps. It rarely works. String stretches, paper does not slide over a knuckle the way metal does, and you will almost certainly wake her up.
The method that goes wrong least often is to borrow a ring she already owns and wears on the right finger, measure the inside diameter across the widest point in millimeters, and send us that number. We convert it to a size. A ring from her right hand is not the same as her left, so if you can, borrow one she wears on the hand you are aiming for.
If you cannot get hold of a ring at all, ask the person most likely to know and least likely to tell her. Her sister usually knows. So does whoever buys her jewelry at birthdays.
Our ring sizing guide covers the measuring itself in more detail, including the things that quietly change the answer — fingers are smallest in the morning and in cold weather, wide bands fit more tightly than narrow ones, and a knuckle wider than the base of the finger means you size to the knuckle.
Third, if you still do not know, just pick one
This is the part people do not expect us to say. If you have tried everything and you are still guessing, order the size you believe is closest and propose anyway.
We would far rather resize a ring in January than have you delay the proposal or spoil the surprise by asking her directly. If it does not fit when she puts it on, tell us the size you need and we resize it. You do not have to return it for a refund and start again.
For reference, the most common women's sizes sit in the middle of the range, so a middle size is a sensible guess if you have nothing else to go on. A ring that is slightly loose can be worn on Christmas morning. One that will not go on at all cannot, so if you are torn between two sizes, go with the larger one.
Two honest caveats. Most rings can be resized, but full eternity bands — where stones run the whole way around the band — generally cannot be resized without being remade, because there is no plain metal to work with. If you are buying an eternity band as a proposal ring and you are guessing at the size, tell us when you order and we will say plainly what your options are. And a ring that has been resized by another jeweler falls outside our returns policy, so come to us first.
What the returns window actually gives you
You have 60 days from delivery to return any piece, and returns are free. The practical effect for a Christmas proposal is that a ring delivered in the week before Christmas is comfortably inside its window well into February. That is enough time to propose, let her live with the ring for a few weeks, and still change the size, the metal or the ring itself if she wants something different.
It is worth saying out loud: plenty of people propose with a ring and then change it afterwards, together. That is not a failure of the proposal. The returns and exchanges page sets out exactly how it works.
Choosing the ring itself
Once the size stops being the problem, the ring is the enjoyable part. A few things that genuinely narrow it down:
- Look at what she already wears. If every piece she owns is yellow gold, a white gold ring will feel like someone else's. Metal color is the thing people notice first and mention least.
- Solid gold, not plated. Everything we make is solid 10K, 14K or 18K gold right through the piece, so it can be resized, repaired and worn for decades. 14K is what most people choose for a ring worn every day.
- Know what the stone is. Lab grown diamonds are chemically and optically identical to mined diamonds and ours are IGI certified. Moissanite is a different stone altogether, not an imitation diamond — very hard, very brilliant, and considerably less per carat; ours is GRA certified. Natural diamonds are GIA certified. The certificate travels with the ring.
- Band width changes the look more than the carat does. A slim band makes the same stone look larger.
If you want somewhere to start, our lab grown diamond engagement rings are where most Christmas proposals in our order book begin, and the shipping and delivery page has the cut-off date and transit times in full.
The short version
Order by Monday 14 December 2026. Borrow a ring she wears and measure the inside diameter if you can. If you cannot, guess slightly large and let us resize it afterwards. You have 60 free days to change your mind about almost everything except the date.
If you are stuck on any of it, email contact@thekaratstore.com and a person will answer you. December is our busiest month and it is also the month we are most used to this exact question.