Compression Socks Levels Explained: What Do mmHg Numbers Mean?
You've probably seen numbers like 15–20 mmHg on compression sock listings and wondered what they actually mean. This guide explains compression levels in plain language, so you can choose with confidence instead of guessing.
What Does mmHg Mean?
mmHg stands for millimeters of mercury, the unit used to measure pressure. On a compression sock, it tells you roughly how much pressure the sock applies at the ankle, where it is firmest. The higher the number, the firmer the squeeze.
Graduated Compression: Why the Design Matters
Most quality compression socks use graduated compression: the pressure is strongest at the ankle and gradually eases toward the top of the sock. This is different from a regular tight sock, which squeezes evenly or unpredictably. Our article on compression socks vs regular socks explains the difference in more detail.
The Common Compression Levels
Exact classifications vary by brand and by country, but these ranges are widely used:
- 8–15 mmHg (light): a gentle feel, often chosen by people who want a little extra support.
- 15–20 mmHg (moderate): a popular everyday level for standing, sitting for long periods and travel.
- 20–30 mmHg (firm): typically used for specific medical situations and usually recommended by a healthcare professional.
- 30–40 mmHg and above (extra firm): medical-grade compression, normally prescribed and properly fitted by a professional.
Which Level Is Right for Everyday Wear?
For day-to-day comfort, many people find a moderate level such as 15–20 mmHg works well: noticeable support without feeling too restrictive. Compribe's knee-high compression socks are designed with graduated 15–20 mmHg support. If you're on your feet all day, our guide to the best compression socks for standing all day covers what else to look for.
Is a Higher Number Always Better?
No. A higher level isn't automatically better, and a sock that's too firm can be uncomfortable and hard to put on. The right level depends on your needs, and fit matters just as much as the number. A well-fitting 15–20 mmHg sock will usually feel better than a poorly fitting firmer one. Check our size guide to get the fit right.
How Long Can You Wear Them?
Many people wear moderate compression through the day, but it depends on you and how you feel. Our article on when to wear compression socks goes into more detail.
When to Talk to a Healthcare Professional
Speak to your doctor before wearing compression socks if you have circulation or vascular problems, diabetes, nerve damage, heart conditions or skin problems, or if you're pregnant. Higher compression levels in particular should be chosen with professional advice. If your socks cause pain, numbness, tingling or a change in skin color, take them off and seek advice.
Key Takeaways
- mmHg measures how firm the compression is at the ankle.
- Graduated compression is firmest at the ankle and eases toward the knee.
- 15–20 mmHg is a common level for everyday comfort.
- Higher isn't always better, and firm medical levels should be chosen with a professional.
- The right size matters as much as the level.
Ready to try a pair? Browse Compribe's compression socks collection.