Getting the Size Right
Including how to find it in secret, and why to err large
Averages Are Useless for One Specific Person
The UK average is L to N for women and P to T for men. That is a genuinely useless fact when you are buying for one particular person, and guessing from it is how rings end up unwearable on the day they matter most.
A ring also has to fit across seasons, temperature, travel, daily swelling and the natural changes of a hand over decades. Sizing is the least glamorous decision in the whole process and one of the two or three most important.
What follows is how to find the real answer, including when it has to stay a surprise.
Ring Size Estimator
Calibrate your screen against a bank card, then lay a ring they already wear over the circles. It takes about a minute and gives a real starting point rather than a guess.
Step one
Calibrate your screen
Hold any bank card against the screen and drag the slider until the outline below matches its long edge exactly. Every bank card in the world is 85.60mm wide, so this makes everything that follows true size.
Step two
Lay a ring over the circles
Use a ring they already wear on the correct finger. Rest it over each circle until the printed line is just hidden inside the band. That match is their size.
Circles cover UK sizes H to V. For anything outside that range, use the full A to Z chart further down this page.
We Post a Free Ring Sizer, Anywhere in the UK
A complimentary plastic sizing belt, delivered free to any UK address, in plain packaging if it needs to stay a secret. Slip it on, read the size, and you have a real measurement rather than an estimate.
It costs you nothing and it removes almost every problem on this page. If you take one thing from this guide, take this.
How to Find Their Size
Order the free sizer
The most accurate route and the one we would always suggest first. Request one here, free to UK addresses, discreetly packaged.
Borrow an existing ring
One worn on that exact finger. Have it measured, or trace the inside circumference precisely. The finger matters: a right-hand ring is rarely the same size as the left.
Ask a trusted confidante
A close friend, sibling or parent who genuinely knows. Keep the circle small, because engagement conversations travel faster than anyone expects.
Propose with a placeholder
A temporary silver ring, then design the real piece together and size it properly. We do this routinely and credit the placeholder against the final purchase.
Measure together
If you can ask directly, visit a jeweller together. Even window shopping reveals a size, and it is by far the most reliable method available.
Use the chart below
Compare a borrowed ring's inside diameter against the millimetre column. A fast starting estimate, though we would still confirm it physically where the plan allows.
Four Discreet Methods
Borrow from another finger
Take a ring they already wear on the right hand or a different finger, then tell us which finger it came from. We can estimate the difference reasonably well.
Take an impression
Press the ring into a bar of soap or a piece of Blu Tack and bring us the impression. It preserves the inside diameter accurately and the ring goes straight back.
Measure while they sleep
Wrap a thin paper strip around the base of the finger and mark the overlap. Less accurate than a borrowed ring, but better than a guess.
Have the sizer sent discreetly
Our sizer arrives in plain packaging with nothing on the outside identifying us, precisely so it can be ordered to a shared address.
Six Things That Throw a Measurement Off
- Wide bands fit tighterA 4mm or wider band contacts more of the finger and needs a slightly larger size. Always size on a band of similar width.
- Prominent knucklesIf the knuckle is larger than the finger base, size to pass the knuckle, then consider sizing beads so it does not spin.
- TemperatureFingers shrink in cold and swell in heat. Measure warm, at rest, ideally in the evening.
- Time of dayFingers are smallest first thing and largest by evening. Measure two or three times across different days.
- Comfort fit changes the answerA domed inner surface slides on more easily, so a comfort-fit band often sizes differently from a flat-interior one.
- Salt, exercise and altitudeAll cause temporary swelling. A measurement taken after a long flight or a gym session will read large.
Err Slightly Large
Resizing down is significantly easier than resizing up. A ring one size too big is wearable and can be adjusted; a ring that will not go on is not wearable at all, and on the day itself that difference matters enormously.
If you are between sizes, take the larger one. This is the single most useful rule on this page.
UK Ring Size Chart
Inside diameter in millimetres, converted to UK, US and European sizing. Measure a borrowed ring across the inside and find the nearest diameter.
| UK | Diameter (mm) | US | EU (circ.) | Notes |
|---|---|---|---|---|
| A | 12.04 | ¼ | 37.8 | Very small |
| B | 12.45 | ¾ | 39.1 | |
| C | 12.85 | 1¼ | 40.4 | |
| D | 13.26 | 1¾ | 42.0 | |
| E | 13.67 | 2¼ | 43.0 | |
| F | 14.07 | 2¾ | 44.0 | |
| G | 14.48 | 3¼ | 45.5 | |
| H | 14.88 | 3¾ | 46.8 | |
| I | 15.29 | 4¼ | 48.0 | |
| J | 15.70 | 4¾ | 49.3 | Common, petite |
| K | 16.10 | 5¼ | 50.6 | |
| L | 16.51 | 5¾ | 51.9 | UK average, women |
| M | 16.92 | 6¼ | 53.1 | UK average, women |
| N | 17.32 | 6¾ | 54.4 | UK average, women |
| O | 17.73 | 7¼ | 55.7 | |
| P | 18.14 | 7¾ | 57.0 | UK average, men |
| Q | 18.54 | 8¼ | 58.3 | UK average, men |
| R | 18.95 | 8¾ | 59.5 | UK average, men |
| S | 19.35 | 9¼ | 60.8 | UK average, men |
| T | 19.76 | 9¾ | 62.1 | UK average, men |
| U | 20.17 | 10¼ | 63.4 | |
| V | 20.57 | 10¾ | 64.6 | |
| W | 20.98 | 11¼ | 65.9 | |
| X | 21.39 | 11¾ | 67.2 | |
| Y | 21.79 | 12¼ | 68.5 | |
| Z | 22.20 | 12¾ | 69.7 |
Round to the nearest 0.05mm where possible. If a measurement falls between two sizes, take the larger.
Resizing, and Its Limits
We will always tell you the limits before any work starts, and tell you honestly when remaking is the better answer.
What we include
One complimentary resize within the first year on non-gemstone-set rings, where the design allows. Free professional inspection for the life of the ring, always.
What cannot always be resized
Full eternity rings, rings set most of the way round, shaped-to-fit bands, engraved bands, mixed-metal construction and certain alternative metals may resize only within a narrow range, or not at all.
When something else is better
A top-heavy ring that spins is usually a weight-distribution problem rather than a size problem, and sizing beads fix it. Loose only in winter? An insert can be added and removed.
Wait before resizing
Observe the fit for two to four weeks across different times of day and temperatures. Many rings that feel wrong for a week are simply being worn in an unusual month.
Do Not Force a Swollen Finger
Raise the hand above the head for a few minutes, cool it, and use soap or hand cream. If the finger is painful, discoloured or numb, seek medical help rather than persisting.
A ring can be cut off safely and, in most cases, repaired invisibly afterwards. Damaged metal is a far smaller problem than a damaged finger.
Sizing Questions We Are Asked Most
How do I find out their ring size without them knowing?
Borrow a ring they wear on another finger and tell us which one, or press it into soap or Blu Tack and bring us the impression. You can also order our free sizer, which arrives in plain packaging. If none of that is possible, propose with a placeholder and size the real ring together.
What is the average UK ring size?
L to N for women and P to T for men. It is worth knowing and worth ignoring: buying for a specific person from an average is how rings end up not fitting. Use it only as a sanity check on a measurement you have taken properly.
Should I size up or down if they are between sizes?
Up, always. Resizing down is straightforward on most designs; resizing up is more involved and sometimes impossible. A ring slightly too large is wearable on the day. A ring that will not go on is not.
Does a wider band need a bigger size?
Yes, usually by around a half size. A wide band contacts more of the finger and fits more tightly than a narrow one of the same nominal size, which is why we size against the profile and width you have actually chosen.
Can a full eternity ring be resized?
Generally not, because the stones run the whole way round and there is nowhere to cut. This is why we are insistent about getting the size right first time on full eternity rings, and why a half eternity is the more forgiving choice if you are unsure.
My ring fits differently in summer and winter. Is that normal?
Entirely. Finger size varies with temperature, time of day, hydration, salt, altitude, exercise and medication. A ring that is loose on a cold morning and snug on a summer evening is behaving exactly as expected. Observe it over a month before deciding anything.
Do you offer a free resize?
One complimentary resize within the first year on non-gemstone-set rings, where the design allows. Gemstone-set, full-eternity, intricate, shaped or engraved designs may not be safely resizable, and we will explain any limits before you commit rather than afterwards.
The Engagement Ring Guide
Sizing in secret, plus budget, the Four Cs, shapes, settings and the bespoke process. Includes a print-accurate ring size estimator.
Round
Pear
Princess
Emerald
Oval
Asscher
Cushion
Marquise
Radiant
Heart
