The short version: compression socks are rated in mmHg — millimetres of mercury — and graduated socks are tightest at the ankle, easing towards the knee. For most healthy travellers on a long flight, 15–20 mmHg is the useful range. Anything at 20–30 mmHg or above is a medical-grade product and is worth a conversation with your doctor first.
This is general information, not medical advice. If you are pregnant, have diabetes, peripheral arterial disease, a history of DVT, or are recovering from surgery, ask a clinician which compression level is right for you before flying.
What the numbers mean
| Level | mmHg | Typically used for |
|---|---|---|
| Light | 8–15 | Everyday tired legs, desk work, light swelling |
| Moderate | 15–20 | Long flights, long drives, standing all day — the usual travel choice |
| Firm | 20–30 | More pronounced swelling, varicose veins, post-travel recovery |
| Medical | 30–40+ | Prescribed conditions; clinician-directed |
Graduated is the word that matters. A sock that squeezes evenly is a tight sock. A graduated sock is tightest at the ankle and eases up the calf, which is what encourages blood back towards the heart rather than trapping it.
Why flying is different from sitting at a desk
Two things happen at altitude. Cabin pressure is lower than at sea level, and you are immobile for hours in a seat that puts pressure on the back of your thighs. Together these encourage fluid to pool in the lower legs — which is why shoes stop fitting on descent, and why your ankles look different on arrival.
Compression addresses the pooling. It does not address the immobility, which is why we tell clients to walk the cabin roughly once an hour when the seatbelt sign allows, and to flex their ankles regularly when it does not.
Which of ours does what
- Anti-Fatigue Compression Socks — everyday anti-fatigue compression in a breathable, moisture-wicking knit. The one to buy if you are not sure.
- Bamboo Graduated Compression Socks — the same graduated support in bamboo viscose, for people who find synthetic knits scratchy.
- Unisex Compression Socks — a lighter athletic knit, and the widest size range in the line.
- Men's Flight Compression Socks — a three-pair pack of flight socks, sized for men.
- 23–32mmHg Graduated Compression Socks — firm 23–32 mmHg graduated compression. This is the medical-grade end of the range; read the caveat above.
- Non-Slip Athletic Travel Socks — not compression, but non-slip soles for hostel floors, yoga studios and the walk to the lavatory at altitude.
How to wear them properly
- Put them on before you leave for the airport, ideally first thing in the morning, before any swelling starts. Putting compression socks onto already-swollen legs is both harder and less effective.
- No wrinkles. A folded band creates a tourniquet effect, which is the opposite of what you want. Smooth them fully.
- Do not roll the top down. Same reason.
- Measure your calf, not just your shoe size. Compression sizing depends on calf circumference. A sock that is too small does not deliver more compression; it delivers the wrong compression in the wrong place.
- Take them off overnight unless a clinician has told you otherwise.
Common questions
Do I need compression socks for a three-hour flight?
Most healthy travellers do not. The benefit grows with the length of the flight; four hours and up is where we usually suggest them.
Are they uncomfortable?
Correctly sized 15–20 mmHg socks feel snug, not painful. Pain, numbness, tingling or colour change means the sock is wrong — take them off.
Can I wear them with sandals?
You can, and plenty of people do. There are worse things than looking sensible on a plane.
Do compression socks prevent DVT?
Compression is one part of reducing risk, alongside movement and hydration — but it is not a guarantee, and it is not a substitute for medical advice if you have risk factors. Speak to your doctor.
How do I wash them?
Cool wash, air dry. Heat destroys elastane, and a compression sock that has lost its elastane is just a sock.
Written by the advisors at WB Travel Associates, a travel agency in Virginia Beach, Virginia. General travel information only — not medical advice. Browse Travel Comfort.
