Compression Class Converter: US mmHg, EU CCL, UK and French Classes
Built by the Compression & Shapewear editorial team from published compression standards, checked 7 October 2026. Informational only; not medical advice.
"Class 1" means different things in different countries. German RAL Class 1 (CCL 1) is 18–21 mmHg, British Class 1 is 14–17 mmHg, French Class 1 is 10–15 mmHg, and the US doesn't use classes at all, just mmHg ranges such as 15–20. Pick the label on your box below to see what it equals elsewhere.
Convert a compression level
Labelled CCL 1–4, KKL 1–4 or Class 1–4. European medical brands such as medi and CzSalus label their garments this way.
18–21 mmHg
≈ 2.4–2.8 kPa at the ankle
United States (mmHg ranges)
Closest match15–20 mmHg (moderate) / 20–30 mmHg (firm)
Mostly 15–20 mmHg (moderate); the edge of your range also touches 20–30 mmHg (firm).
United Kingdom (British Standard)
Closest matchClass 2
Sits inside Class 2 (18–24 mmHg).
France (ASQUAL)
Closest matchClass 2 / Class 3
Mostly Class 2 (15–20 mmHg); the edge of your range also touches Class 3 (20–36 mmHg).
What this level is typically used for
15–20 mmHg
- Day-to-day relief from achy, heavy, slightly swollen legs
- Busy, active days and travel
- During pregnancy, to help prevent varicose and spider veins
20–30 mmHg
- The level most commonly prescribed by doctors
- Varicose veins and mild oedema
- After procedures such as sclerotherapy
Typical uses as listed by SIGVARIS for each US mmHg level.
Looking for compression leggings in this range?
Our sister site's size finder compares five brands' official size charts from one set of measurements, including which brands go large enough.
Find your size →Compression classes by country
Ankle pressure for each class as defined by each standard, checked 7 October 2026. The US has no class standard; garments are sold by mmHg range.
| Standard | Class 1 | Class 2 | Class 3 | Class 4 |
|---|---|---|---|---|
| Germany / EU medical (RAL)RAL-GZ 387 (German quality mark; labelled CCL, KKL or Class) | 18–21 mmHg | 23–32 mmHg | 34–46 mmHg | 49+ mmHg |
| United Kingdom (British Standard)BS 6612:1985 | 14–17 mmHg | 18–24 mmHg | 25–35 mmHg | Not defined |
| France (ASQUAL)French ASQUAL / IFTH classification | 10–15 mmHg | 15–20 mmHg | 20–36 mmHg | 36+ mmHg |
| United StatesSold by mmHg range | 8–15, 15–20, 20–30, 30–40 and 40–50 mmHg | |||
Why the same "Class 1" isn't the same
There is no single international standard for compression stockings. A planned European standard (draft ENV 12718) was abandoned in 2005 without agreement, so the British, German and French standards still run side by side. They also measure pressure with different laboratory methods (HATRA in the UK, HOSY in Germany, IFTH in France), which is why a class number on its own can't be compared across countries.
In practice: a European CCL 1 legging (18–21 mmHg) is a little firmer than a US 15–20 mmHg one, a British Class 2 (18–24 mmHg) is roughly the same as a German CCL 1, and French Class 3 covers everything from 20 to 36 mmHg. When you compare products, compare the mmHg figure, not the class number.
What each mmHg level is typically used for
8–15 mmHg: Mildly aching and tired legs; Support when standing or sitting for long periods.
15–20 mmHg: Day-to-day relief from achy, heavy, slightly swollen legs; Busy, active days and travel; During pregnancy, to help prevent varicose and spider veins.
20–30 mmHg: The level most commonly prescribed by doctors; Varicose veins and mild oedema; After procedures such as sclerotherapy.
30–40 mmHg: Moderate to severe oedema and lymphoedema; More serious varicose veins; DVT and post-thrombotic syndrome care.
40–50 mmHg: Severe chronic venous insufficiency; The most severe DVT and post-thrombotic cases.
Uses as listed by SIGVARIS. For help choosing a level for work, travel or pregnancy, see our guide to choosing a compression level.
Who should get advice before wearing compression
JOBST lists these as conditions in which its medical legwear should not be worn:
- Advanced peripheral arterial disease (poor arterial circulation in the legs)
- Uncontrolled congestive heart failure
- Untreated septic phlebitis
- Phlegmasia coerulea dolens
If you have diabetes, numbness in your feet, a skin condition on your legs or any heart or circulation problem, talk to your doctor before buying compression, whatever the class.
Method and sources
Class ranges are taken from the published standards as reported in the sources below, not from retailer copy. Where sources disagreed, we used the value given by a clinical journal or the manufacturer that applies the standard. kPa values use 1 mmHg = 0.1333 kPa.
- York K, Freeman N. Simplifying hosiery prescribing with the Hosiery Hunter selection tool. Wounds UK 2019; 15(1): 98–99, Table 1 (British, German RAL and French standards), checked 7 October 2026
- Altmeyer P, Reich-Schupke S. Compression stocking, medical. Altmeyers Encyclopedia (country comparison incl. France and USA), checked 7 October 2026
- medi: Compression classes for compression stockings (CCL I–IV), checked 7 October 2026
- SIGVARIS: Compression levels and indications (US mmHg levels), checked 7 October 2026
- JOBST / BSN medical Ready-to-Wear Medical Legwear Selection Chart BSN0228 (contraindications), checked 7 October 2026
Frequently Asked Questions
Is EU Class 1 the same as 15–20 mmHg?
Not quite. German RAL Class 1 (CCL 1), used by European medical brands such as medi, is 18–21 mmHg, which is slightly firmer than the US 15–20 mmHg level. French Class 2 is the closest match to US 15–20 mmHg, and British Class 1 is lighter at 14–17 mmHg.
What is CCL 2 in mmHg?
CCL 2 under the German RAL standard is 23–32 mmHg at the ankle. It overlaps mostly with the US 20–30 mmHg level, and its upper end reaches into 30–40 mmHg.
Why do compression classes differ between countries?
There is no single international standard. The British, German and French standards each define their own pressure ranges and use different laboratory test methods (HATRA, HOSY and IFTH), so the classes are not directly interchangeable. The US labels garments by mmHg range rather than by class.
Do I need a prescription for 20–30 mmHg?
In the US no law requires one, but SIGVARIS notes that 20–30 mmHg is the level doctors prescribe most often and that most pharmacies won't dispense higher-level compression without a prescription. Talk to your doctor before starting 20–30 mmHg or firmer, especially if you have a circulation, heart or skin condition.
What is 15–20 mmHg in kPa?
About 2.0–2.7 kPa. One mmHg equals 0.1333 kPa, so multiply the mmHg figure by 0.1333.
Know your level? Compare the brands that make it.
Compare compression brands