Ring Sizing
Find your perfect fit
Buying a ring online doesn't have to mean guessing your ring size.
Whether you're buying a ring for yourself, choosing a gift, or adding a new piece to your jewellery collection, our UK ring size guide will help you find the closest fit.
The most accurate way to determine your ring size is to have your finger professionally measured by a jeweller. If that's not possible, you can use one of the methods below to estimate your size at home.
Our Ring Sizes
Collective & Co. uses UK ring sizes, which are represented by letters.
If you're familiar with US or European ring sizes, use our conversion chart below to find the closest UK equivalent.
UK Ring Size Conversion Chart
| UK Size | Approx. Inside Diameter | Inside Circumference | US Size | EU Size |
|---|---|---|---|---|
| H | 14.65 mm | 46.0 mm | 3¾ | 46 |
| I | 15.04 mm | 47.3 mm | 4¼ | 48 |
| J | 15.40 mm | 48.4 mm | 4⅝ | 49 |
| K | 15.80 mm | 49.6 mm | 5⅛ | 50 |
| L | 16.10 mm | 50.6 mm | 5½ | 51 |
| M | 16.51 mm | 51.9 mm | 6 | 52 |
| N | 16.92 mm | 53.2 mm | 6½ | 54 |
| O | 17.35 mm | 54.5 mm | 7 | 55 |
| P | 17.75 mm | 55.8 mm | 7½ | 56 |
| Q | 18.19 mm | 57.2 mm | 8 | 58 |
| R | 18.61 mm | 58.5 mm | 8⅝ | 59 |
| S | 19.10 mm | 60.0 mm | 9⅛ | 60 |
| T | 19.51 mm | 61.3 mm | 9⅝ | 61 |
| U | 20.02 mm | 62.9 mm | 10¼ | 63 |
| V | 20.32 mm | 63.8 mm | 10⅝ | 64 |
| W | 20.76 mm | 65.2 mm | 11⅛ | 65 |
| X | 21.18 mm | 66.5 mm | 11⅝ | 66 |
| Y | 21.49 mm | 67.5 mm | 12 | 68 |
| Z | 21.89 mm | 68.8 mm | 12½ | 69 |
Measurements are approximate. Ring fit can vary slightly depending on the design, band width and shape of the ring.
How to Measure Your Ring Size at Home
Method 1: Measure a Ring You Already Own
If you already have a ring that fits the finger you want to wear your new ring on, this can be one of the easiest ways to estimate your size.
Step 1
Choose a ring that fits comfortably on the same finger.
Step 2
Measure the inside diameter of the ring across the widest point, from inside edge to inside edge.
Measure in millimetres (mm).
Step 3
Compare your measurement with our ring size chart above.
Important
Make sure you measure the inside of the ring, rather than the outside edge. Even a small difference in measurement can affect the size you select.
Method 2: Measure Your Finger
You can also estimate your ring size by measuring the circumference of your finger.
What you'll need:
- A thin strip of paper or non-stretchy string
- A ruler
- A pen
Step 1
Wrap the paper or string around the base of the finger where you intend to wear the ring.
It should feel comfortably snug — not tight and not loose.
Step 2
Mark the point where the paper or string meets.
Step 3
Lay it flat and measure the length up to your mark in millimetres.
This measurement is your approximate finger circumference.
Step 4
Use the Inside Circumference column in our chart to find the closest UK ring size.
This method is also commonly recommended by jewellers, although a professional ring sizer will provide a more accurate result.
Tips for Getting the Most Accurate Ring Size
Your fingers naturally change size throughout the day, so when measuring at home, keep the following in mind.
Measure when your hands are at a normal temperature
Cold weather can cause your fingers to contract, while heat can cause them to swell.
Measure more than once
Take your measurement at different times of the day and compare the results.
Don't measure immediately after exercise
Exercise and heat can temporarily cause your fingers to swell.
Measure the correct finger
Your fingers aren't necessarily the same size on both hands, so always measure the specific finger you intend to wear the ring on.
Consider your knuckle
If you have larger knuckles, your ring needs to be large enough to pass over the knuckle while still fitting comfortably at the base of your finger.
Don't pull the measuring strip too tightly
The measurement should reflect the way a ring will actually sit on your finger.
Between Two Ring Sizes?
If your measurement falls between two sizes, we generally recommend considering the larger size, particularly if:
- The ring has a wider or thicker band
- Your fingers tend to swell
- You live somewhere warm
- The ring needs to pass over a larger knuckle
- You prefer a slightly more relaxed fit
However, the ideal choice can depend on the specific ring design.
Ring Width Can Affect Fit
Not all rings fit the same way.
A thin, delicate band generally feels different from a wider or heavier ring, even when both are technically the same size.
Wider bands cover more of your finger and can feel tighter than a narrow band in the same size. For wider or chunky ring designs, you may prefer to size up slightly.
This is why our ring size guide should be used as a starting point rather than an absolute guarantee of fit. South African jewellers similarly note that ring style and band width can affect how a ring fits.
What Is a UK Ring Size?
UK ring sizes use letters rather than numbers.
For example:
- UK L ≈ US 5½
- UK M ≈ US 6
- UK N ≈ US 6½
- UK O ≈ US 7
- UK P ≈ US 7½
- UK Q ≈ US 8
So, if you've previously been told you're a US size 6, your approximate UK ring size is M, with an inside circumference of approximately 51.9 mm.
What If I Already Know My Ring Size in the US?
No problem.
Use the US Size column in our conversion chart to find the closest UK letter size.
For example:
US 6 → UK M
US 7 → UK O
US 8 → UK Q
US 9 → UK S
US 10 → UK U
Please note that international ring-size conversions are approximate, so measuring your finger or an existing well-fitting ring is preferable where possible.
Buying a Ring as a Gift?
If you're buying a ring for someone else and don't know their size, don't panic.
Here are a few ways to find out discreetly:
Borrow one of their rings
If you can get hold of a ring they already wear on the same finger, use it to measure the inside diameter.
Ask someone close to them
A partner, parent, sibling or friend may already know their ring size.
Check their jewellery box
Look for a ring they regularly wear and have it professionally measured by a jeweller.
Don't guess based on height or weight
There is no reliable way to determine someone's ring size from their height, weight or general appearance.
My Ring Doesn't Fit — What Should I Do?
If your ring doesn't fit as expected, don't force it over your finger.
If it's too tight, remove it carefully and contact us about your options.
If it's slightly too loose, you may find that the ring feels different depending on the temperature of your hands or the time of day.
If you've purchased from Collective & Co. and are unsure about the fit, contact us before returning your ring, and we'll be happy to help you determine the best next step.
Please also refer to our Returns & Refund Policy for information about returning or exchanging eligible items.
A Note About Ring Sizing
Ring sizing is not an exact science when measured at home.
The measurements in this guide are intended to help you select the closest size, but the most accurate way to determine your ring size is to have your finger measured by a professional jeweller using a calibrated ring sizer.
Your ideal size can also vary depending on the finger, hand, ring width, ring design and time of day.
If you're between sizes, have a particularly wide band or are unsure about your measurement, we recommend getting professionally measured before ordering.
Ring Size FAQs
What is a UK size 6 ring?
The UK uses letter sizing rather than numbered sizes. A US size 6 is approximately equivalent to a UK M, with an inside circumference of approximately 51.9 mm.
What is a UK size M ring?
A UK M ring has an approximate inside circumference of 51.9 mm and an inside diameter of approximately 16.5 mm. It is approximately equivalent to a US size 6.
How do I measure my ring size at home?
Wrap a thin strip of paper or non-stretchy string around the base of your finger, mark where it meets, then measure the length in millimetres. Compare your measurement with the circumference column in our ring size chart.
Is UK ring size the same as US ring size?
No. UK ring sizes use letters, while US ring sizes generally use numbers. Use a conversion chart to find the closest equivalent.
Is ring size based on diameter or circumference?
Both measurements can be used. Inside diameter measures straight across the inside of the ring, while inside circumference measures around the inside of the ring. Our chart includes both measurements to make finding your size easier.
Should I size up if I'm between ring sizes?
If you're between sizes, choosing the larger size can be more comfortable, particularly for wider bands or if your fingers tend to swell. However, the best choice depends on the ring design.
Do wider rings fit differently?
Yes. A wider band can feel tighter than a narrow band in the same nominal ring size. You may need a slightly larger size for wider or chunky rings.
Do fingers change size during the day?
Yes. Finger size can vary with temperature, activity and other factors. For the most reliable home measurement, measure your finger when your hands are at a normal temperature and repeat the measurement more than once.
Still Unsure of Your Ring Size?
We're happy to help.
If you're between sizes or unsure which ring size to choose, contact the Collective & Co. team before placing your order and we'll do our best to guide you.
Find your fit. Find your favourite.