The four ranges
| Level | Typical use | Prescription? |
|---|---|---|
| 8–15 mmHg | Very mild. Tired legs, light desk-day fatigue. Barely more than a firm sock. | No |
| 15–20 mmHg | Mild. Occasional swelling, short flights, first-time users, mild pregnancy discomfort. | No |
| 20–30 mmHg | The everyday standard. Daily swelling, aching and heavy legs, varicose veins, 12-hour shifts, long-haul flights, running recovery. | No (usually) |
| 30–40 mmHg + | Medical grade. Severe venous insufficiency, lymphoedema, post-DVT, venous ulcers. | Yes — fit under clinical supervision |
Why TrueFit is 20–30 mmHg
It's the range with the widest evidence base for the symptoms most people actually have: swelling, aching, heaviness and vein discomfort. Below it, many people notice nothing. Above it, comfort drops sharply and you need clinical fitting.
Remember the number describes the ankle. TrueFit measures 20–30 mmHg at the ankle and eases to roughly 12–16 mmHg at the calf — that gradient is what moves blood upward. See how compression socks work.
Choosing your level
- Never worn compression, mild symptoms? 15–20 mmHg is a gentle start, but most people move up.
- Daily swelling, standing job, visible veins, frequent flying? 20–30 mmHg.
- Diagnosed venous disease, lymphoedema or post-clot? See a clinician; you likely need 30–40 mmHg fitted properly.
Level means nothing if the size is wrong
A 20–30 mmHg sock that's a size too small delivers far more than 30 mmHg and can cut circulation instead of helping it. A size too large delivers almost nothing. Measure your calf: size guide.