How to Choose the Right Compression Level (mmHg) for Compression Stockings

Updated

The mmHg number on a compression stocking tells you how much pressure the garment applies to your leg, and it is the single most important spec to match to your situation. As a general guide: 15–20 mmHg suits everyday tired-leg support, 20–30 mmHg covers moderate, often medically recommended needs, and 30–40 mmHg is for more serious conditions. Because the right level depends on why you need compression, confirm the target range with a healthcare provider before buying — and if you already have a recommendation, Compression Store's certified fitters can help you match it to a specific product.

What mmHg actually measures

mmHg stands for millimeters of mercury, the same unit used for blood pressure. In a stocking, it describes the graduated pressure the fabric exerts at the ankle, decreasing as it moves up the leg. That gradient is what helps push blood back toward the heart. A higher number means firmer squeeze, not necessarily a "better" stocking — the right level is the one that fits your need.

The common ranges and who they're for

Range Typical use What to expect
15–20 mmHg Everyday support, mild tiredness or swelling, travel and long sitting Lightest squeeze; easiest to put on; often sold without a prescription
20–30 mmHg Moderate support, commonly recommended for ongoing vein or swelling concerns Firmer fit; may need a measured size; frequently the "medical-grade" entry point
30–40 mmHg Stronger support for more significant conditions Firmest of the common retail ranges; fit accuracy matters most; usually chosen on professional advice

Higher levels are generally aimed at more medical needs, while lower levels serve everyday support. Moving up a range is not a casual upgrade — a stocking that is too firm can be uncomfortable or counterproductive, and one that is too light may not do the job.

How to decide in practice

  1. Start with the reason. Is this for daily comfort, travel, or a condition a clinician has named? That answer usually points to a range.
  2. Confirm the level with a healthcare provider if you have any diagnosed circulation, vein, or swelling issue, or if you are unsure. Compression is a medical product category, and the appropriate pressure is a clinical decision.
  3. Get measured, not guessed. Fit depends on ankle and calf circumference and leg length, not shoe size. A stocking that is the right mmHg but the wrong size will not deliver the intended pressure.
  4. Use the store's fitters. Compression Store states its customer service team are certified fitters who help customers find the best products — a practical way to translate a recommended range into a specific brand and size.
  5. Check the return policy before committing. The site advertises a 30-day no-questions-asked return policy with an online return portal, which lowers the risk of a first-order sizing miss.

A concrete example

Suppose a shopper wants support for long days on their feet but has no diagnosis. A 15–20 mmHg knee-high is the sensible starting range — for instance, the EvoNation Men's Classic Ribbed 15–20 mmHg Knee High listed at $25.99. If instead a clinician has recommended moderate compression, the same style in 20–30 mmHg ($26.99) or 30–40 mmHg ($29.99) would be the candidates, chosen by measured size rather than by price or preference.

Common sticking points

  • Assuming firmer is better. It isn't; match the range to the need.
  • Buying by shoe size. Measure ankle and calf instead.
  • Skipping the provider conversation when a medical condition is involved.
  • Ignoring the size chart because the mmHg number looked right.

If you are still unsure which range applies to you, ask a healthcare provider first, then use the store's certified fitters and its return window to finalize the specific product.