Compression Sock Sizing Across Brands: When Sigvaris Small Isn't JOBST Small

Last reviewed: August 26, 2026 · Compression Socks Canada Team

Compression sock sizing is not generic. A "medium" in one brand is rarely the same as a "medium" in another. The size labels look familiar — small, medium, large, extra-large — but the actual circumference and length ranges behind those labels vary between manufacturers and even between product lines within the same manufacturer. For most everyday socks this kind of variation is a minor inconvenience. For compression socks, it is the difference between a product that delivers the labelled pressure and one that bunches at the ankle, rolls at the cuff, or sits too loose to do its mechanical job. This article walks through how compression sizing works, why brands differ, how to measure correctly, and how to navigate the sizing process when switching between Sigvaris, JOBST, Actimove, Mobilis, or another brand. It is general educational content and not a substitute for advice from a trained compression fitter.

Why compression sizing exists in the first place

The mechanical purpose of a compression stocking is to deliver a specific graduated pressure profile along the leg. That pressure is the product of the fabric's tension and how much the fabric is stretched when worn. If the stocking is too small for the leg, it stretches too much, which can produce uncomfortable hot spots and may distort the pressure gradient. If the stocking is too large, it does not stretch enough and delivers less pressure than labelled. The right fit places the leg inside the design window that the manufacturer engineered.

That design window is described by a set of body measurements — ankle, calf, sometimes thigh, and leg length — paired with the manufacturer's specific size chart. The same words ("small," "medium") map to different measurement windows across brands.

What gets measured

For knee-high stockings, two measurements are essential:

• Ankle circumference (cB): measured at the narrowest point above the ankle bone, typically two centimetres above the malleolus.
• Calf circumference (cC): measured at the widest point of the calf.

A third measurement — leg length from the floor to one finger-width below the back of the knee crease — determines whether you need a regular, petite, or long version.

For thigh-high stockings, two additional measurements come into play:

• Thigh circumference (cG): measured at the widest point under the gluteal fold.
• Leg length from floor to gluteal fold.

For pantyhose, hip and waist measurements are added.

How to measure correctly at home

1. Measure in the morning before the legs accumulate the day's swelling.
2. Use a flexible cloth tape measure, not a metal one.
3. Stand with weight evenly distributed for the ankle and calf measurements.
4. Measure ankle at the narrowest point, just above the bony part.
5. Measure calf at the widest point, typically about a third of the way up the calf from the ankle.
6. Measure leg length from floor to one finger-width below the back of the knee crease.
7. Record the measurements in centimetres. Most modern size charts use centimetres rather than inches.
8. Compare against the specific product's size chart, not a generic one.

If two measurements land in different size columns, the larger circumference usually decides the size. If you are at the boundary between sizes, a trained fitter can help decide.

Why brands differ in sizing

Several factors lead to inter-brand sizing differences:

• Different geographies. European-headquartered brands often design around European leg-shape distributions, which differ slightly from North American.
• Different knit constructions. Round-knit versus flat-knit and different yarn blends produce different stretch behaviours.
• Different design windows. Even within a single brand, an everyday cotton sock and a sheer dress hosiery may use different measurement boundaries.
• Different sizing philosophies. Some brands cluster more sizes around the average; others spread them more evenly.

The result is that a customer who fits Sigvaris medium may need JOBST large or Actimove small depending on the specific product. None of the brands are wrong. Each has internally consistent sizing that works when paired with the right measurements.

Sigvaris sizing notes

Sigvaris uses ankle circumference and calf circumference as the primary inputs, with leg length determining regular versus petite (short) versions. Their charts use centimetres. Different Sigvaris product lines — Essential, Comfort, Soft Silhouette, Style, Cotton, Linen, Sea Island Cotton, Sheer, and others — use overlapping but not identical size windows. Browse the broader Sigvaris collection.

JOBST sizing notes

JOBST also uses ankle and calf circumferences as primary inputs. JOBST sometimes uses slightly different naming for size letters (such as US-style S, M, L vs European-style I, II, III). Several JOBST product lines exist — Opaque, UltraSheer, ForMen, SensiFoot, ActiveWear, Bella Lite, FarrowWrap — each with its own chart. Browse the broader JOBST collection.

Actimove sizing notes

Actimove's orthopedic supports and bracing products have different sizing systems entirely from compression hosiery. For ankle, knee, elbow, and wrist supports, size is typically based on the circumference of the joint being supported. Browse the Actimove collection.

Mobilis by Sigvaris sizing notes

The Mobilis by Sigvaris line follows the Sigvaris sizing philosophy with specific options for higher-coverage and lymphedema-oriented products. Browse the Mobilis by Sigvaris collection.

What goes wrong when sizing is off

Common signs that a stocking is the wrong size:

• Bunching at the ankle. Suggests the ankle is too narrow for the stocking's design window.
• Rolling at the cuff. Often a fit issue at the calf or a stocking that has lost elastic recovery.
• Cutting in at the calf cuff. The calf may be larger than the design window allows.
• Sliding down during the day. Often a leg-length issue; the stocking may be too long.
• Pinching across the foot. The size may be too small overall, or the toe construction is incompatible with the foot shape.
• Mark lines after removal. Light marks are normal; deep marks indicate the stocking is too tight in that area.
• End-of-day symptoms returning. Suggests the stocking is delivering less pressure than expected, which can be a sizing or a wear-out issue.

The case for a trained fitter

For first-time buyers, people with diagnosed conditions, and anyone switching brands, a trained compression fitter is worth seeking out. Fitters bring:

• Accurate measurements taken with the correct technique.
• Knowledge of product lines and which products suit which body shapes.
• Ability to identify situations where a custom-fit garment is needed instead of off-the-shelf.
• Awareness of skin, arterial, and other clinical factors that affect product choice.

Authorized Canadian retailers typically have trained staff or can refer to a certified lymphedema therapist for more complex needs.

When off-the-shelf is not enough

Several situations call for custom-fit garments rather than off-the-shelf:

• Significantly irregular leg shape. Common in stage 2 and 3 lymphedema.
• Bariatric sizing outside the standard size charts.
• Specific functional requirements such as post-burn pressure garments.
• Leg measurements that consistently fall between sizes across multiple products.
• Very long or very short legs outside standard length ranges.

Custom flat-knit garments are designed and produced specifically for the wearer's measurements. For more on this category, see our lymphedema stages article.

Tips for switching brands

If you have worn one brand for a while and are considering another:

• Re-measure your legs. They may have changed since you were last measured.
• Do not assume the same letter size will fit. A Sigvaris medium may not be a JOBST medium.
• Buy one pair first. Test the fit and comfort before buying a full rotation.
• Compare the actual measurement windows, not just the labels.
• Talk with a fitter if you are between sizes.
• Give the new stocking a few wears. The first day in a new brand can feel different even when the fit is correct.

What to do when nothing seems to fit

If multiple off-the-shelf products from multiple brands feel wrong, the most likely explanations are:

• The measurements are incorrect.
• The body has changed since the last measurement.
• An irregular leg shape that off-the-shelf cannot accommodate.
• A specific medical situation that needs a fitter or therapist's input.

A re-measurement by a trained fitter, possibly followed by a referral to a certified lymphedema therapist, often resolves the situation.

Putting it together

Compression sock sizing is precise because the mechanical effect of the product is precise. The size labels are simple — small, medium, large — but the underlying measurement windows vary between brands and even between product lines within a brand. The right approach is to measure correctly, use the specific product's size chart, and test the fit with a single pair before committing to a rotation. When switching brands, expect the size label to be different even when the fit is the same. When measurements fall between sizes or the body does not match off-the-shelf assumptions, a trained fitter or certified lymphedema therapist is the right next step. With the right size, compression delivers exactly what it is engineered to do. With the wrong size, it delivers something less or different — and the wearer often gives up on a product that could have worked with a better fit.

Frequently asked questions

Why do brands have different sizing?

Different geographies, knit constructions, design windows, and sizing philosophies produce internally consistent but inter-brand-different sizing.

Do I need to be re-measured to switch brands?

Yes. The same body measurements may map to different sizes in different brands.

When should I get measured by a fitter rather than measuring at home?

For first-time buyers, for diagnosed conditions, for irregular leg shapes, and any time off-the-shelf does not seem to fit.

What if my ankle and calf are in different size columns?

The larger circumference usually determines the size, but a fitter can help with the decision.

Are off-the-shelf sizes adequate for lymphedema?

Often for stage 1; usually not for stage 2 and 3, which typically require custom flat-knit garments.

What if my legs are between standard lengths?

Many manufacturers offer petite/short and long variants. For legs outside these ranges, custom garments may be required.

Related reading

• Finding the perfect fit: sizing guide
• How to measure for compression socks
• Compression sock sizing guide

This article is general educational content. For diagnosed conditions or irregular sizing, work with a trained compression fitter or certified lymphedema therapist.