Compression sock size chart and how to measure
Quick answer: You need three numbers — your ankle at its narrowest, your calf at its widest, and the floor-to-below-knee length. Take them first thing in the morning, then match them to the range given for the product you are buying. If you fall between two sizes, go up. Not sure? Email us the two circumferences and we will tell you which size to order.
How to measure
A soft tape measure, the sort you use for clothes, and two minutes. Measure first thing in the morning if you can, before your legs have had a busy day, and keep the tape snug without pressing it in.
| Measurement | Where to take it | Why it matters |
|---|---|---|
| Ankle circumference | Around the narrowest part, just above the ankle bone | This is where the sock is firmest, so it sets the bottom of your size range |
| Calf circumference | Around the widest part of the calf | The number that decides the fit. Buy to this one |
| Length (knee-highs) | Floor to just below the bend of the knee | Tells you whether a knee-high will sit below the crease rather than on it |
| Shoe size | Your usual UK size | Useful as a cross-check on foot length, and no more than that |
Measure both legs. They are rarely identical, and you buy to the larger one.
Write your numbers down
Keep these somewhere you can find them. Every future order becomes a thirty-second decision.
| Left leg | Right leg | |
|---|---|---|
| Ankle (cm) | ||
| Calf (cm) | ||
| Floor to below knee (cm) |
Why shoe size is not enough
A compression sock is fitted at the calf. Your shoe size describes your foot.
Two people who both take a UK 6 can have calves several centimetres apart, and that difference is what decides whether a sock sits comfortably or rolls down. It is the single most common reason a pair does not work out — and it is why we ask for centimetres rather than a shoe size. The sizing and fit guide goes into this in more depth.
There is no single industry chart
This is worth saying plainly, because it saves people money.
Every manufacturer sets its own size bands. A medium in one range can be a small in another, so knowing you are "a medium" is not information you can safely act on. What travels between ranges is your own measurement in centimetres.
So match your numbers to the range stated for the item you are buying. Where a product page does not give those ranges, send us your ankle and calf measurements and we will check them against the range for you before you order.
Choosing the length and style
| Style | Sits where | Best for |
|---|---|---|
| Knee-high | Just below the knee crease | Travel, work shifts and everyday support |
| Over-knee | Above the knee | Extra coverage and a secure stay-up feel |
| Ankle or low-cut | At the ankle | Trainers, gym sessions and warmer days |
| Open-toe | Knee-high with the toes free | Sandals, hot weather and breathing room |
| Footless | Calf only | Support with your own choice of sock |
| Zip-up | Knee-high with a side zip | Anyone who finds pulling socks on hard work |
Browse by length in knee-high and over-knee, ankle and low-cut, open-toe and footless or zip-up and easy-on.
Wider calves and plus sizes
If your calf measurement sits at or beyond the top of a standard range, you want a cut made for it rather than the next size up of the same sock. A standard sock in a larger size is usually longer in the foot, not wider at the calf, which is not the problem you are solving.
Our plus-size range is cut wider at the calf and the ankle, and the wide-calf favourites and ombre wide-calf socks are made on a wider last throughout.
How firm should they feel? A word on mmHg
You will see mmHg next to compression socks, and it puts a lot of people off.
It describes how firm the sock is, in millimetres of mercury. A moderate 15–20 mmHg is the level most people choose for travel, work, sport and everyday comfort. A well-fitted sock at that level feels supportive and comfortable all day, which is the whole point.
Firmness is not a substitute for fit. A firmer sock in the wrong size is less comfortable, not more effective.
How they should feel on
- Snug and even from ankle to calf, firmest at the ankle.
- No dig at the top band. A ridge or a red line means the calf is too tight.
- No sliding down. That usually means the calf is too loose, not that the sock is faulty.
- Nothing bunching at the ankle, which points to too much length.
- Comfortable after an hour. That is the real test, not the first thirty seconds.
If you are still not sure
Send us the two circumferences and we will tell you which size to order. Email info@happylegscompressionsocks.co.uk and a real person replies, usually the same working day, Monday to Friday.
And ordering is not a commitment to a guess. You have 30 days to send anything back, we pay the return postage, and the refund goes out within 5 working days of the parcel reaching us.
Common questions
What measurements do I need for compression socks? Three: the circumference of your ankle at its narrowest point just above the ankle bone, the circumference of your calf at its widest point, and - for knee-highs - the length from the floor to just below the bend of your knee. Take them first thing in the morning with a soft tape, snug but not pressing in.
Why is my shoe size not enough? Shoe size describes your foot, and the fit of a compression sock is decided at the calf. Two people with the same shoe size can have calves several centimetres apart, which is why a sock chosen on shoe size alone is the most common reason a pair grips at the top or slides down.
What if I am between two sizes? Go up. A slightly roomier sock stays comfortable all day, while one that is slightly too small digs in at the top band and gets taken off by lunchtime. If your two legs measure differently, buy to the larger one.
Do all compression socks use the same size bands? No, and this is the part worth knowing. Every manufacturer sets its own ranges, so being a medium in one range tells you very little about another. Always match your own centimetre measurements to the range stated for the product you are buying.
How do I find my size if the product page does not list the ranges? Email us your ankle and calf measurements in centimetres and we will tell you which size to order. We reply the same working day, Monday to Friday. If it still is not right, you have 30 days to send it back, we pay the return postage, and the refund goes out within 5 working days of the parcel reaching us.
Which length should I choose? Knee-high suits travel, work shifts and everyday wear. Ankle or low-cut suits trainers and warmer days. Open-toe leaves the toes free for sandals and hot weather, footless covers the calf only so you keep your own socks, and a zip-up is for anyone who finds pulling socks on hard work.