You order a size 42 jean from two different websites, and one barely fits while the other is loose at the waist. The problem lies neither with the body nor the measuring tape, but with the complete absence of binding standards for size numbers in France. Understanding what a size 42 really entails requires going back to centimeters, not labels.
Size 42 Waist: What Commercial Grids Don’t Tell You
In France, no law requires brands to use a common scale for numbering their sizes. The old AFNOR references, based on outdated measurement campaigns, still serve as a foundation for many manufacturers. The discrepancy with current body shapes is documented: the average waist circumference of French women has increased by about 3 cm over twenty years according to CNM 2025 data, without commercial grids keeping pace.
The concrete result: the same woman can fluctuate between sizes 40 and 44 depending on the brand, even though her measurements haven’t changed by a centimeter. A size 42 from a fast-fashion brand has no obligation to correspond to that of a high-end ready-to-wear brand.
To understand size 42 and avoid unpleasant surprises, it’s more efficient to think in centimeters rather than label numbers.
Measurements in Centimeters for Women’s Size 42
The most common grids in French ready-to-wear associate women’s size 42 with the following ranges:
- Chest circumference: between 96 and 101 cm, measured horizontally at the fullest part of the bust, without compression
- Waist circumference: between 83 and 88 cm, taken at the natural waist (above the navel, where the torso bends sideways)
- Hip circumference (or pelvis): between 105 and 111 cm, measured at the widest part of the hips
These ranges come from common charts in French ready-to-wear. They vary significantly from one brand to another, and this is precisely the issue when shopping online.
How to Take Your Measurements Without Distorting the Result
Use a flexible measuring tape, placed directly on the skin or over thin underwear. The tape should remain horizontal and not drop down the back. Stand upright, arms at your sides, without sucking in your stomach or puffing out your chest.
Measuring in the morning can distort the waist measurement downwards, as the body is slightly dehydrated after the night. It’s better to take measurements in the middle of the day for a result that is more representative of daily reality.
Men’s Size 42: A Different Logic
For men, size 42 does not refer to the same build at all. For tops (t-shirts, sweaters, jackets excluding shirts), a size 42 generally corresponds to size L, with a chest circumference around 96 to 104 cm according to common grids.
For shirts, size 42 refers to the neck circumference. For pants and jeans, the number 42 indicates the waist circumference in centimeters divided by two, resulting in a real waist of about 84 cm. Returns vary on this point depending on cuts: a slim jean will fit tighter than a straight chino labeled the same way.
The classic trap: confusing a size 42 pant with a 42 US. In US sizing (often indicated on jeans), size 42 corresponds to a much larger waist, close to a French size 52.
International Size Correspondence for Size 42
The French size 42 does not translate the same way depending on the country of origin of the garment. Here are the most common equivalents for women’s clothing:
| France | Italy | United Kingdom | United States | International Size |
|---|---|---|---|---|
| 42 | 46 | 14 | 10 | L |
For men, the correspondence varies depending on the type of garment (top, bottom, shirt). A French size 42 in men’s pants often equates to a US size 32 in waist circumference.
Always check the size guide specific to each site remains the only reliable method. Generic charts provide a rough estimate, not a guarantee.
Choosing Between Two Sizes: The Deciding Criteria
When in doubt between a 40 and a 42 (or a 42 and a 44), the reflex to take “in between” doesn’t work. The choice depends on three concrete factors.
- The material: a fabric with elastane allows for half a centimeter less, while rigid cotton or linen won’t give
- The cut: a straight or oversized cut tolerates one size down, while a fitted or tailored cut requires taking the size corresponding to the largest measurement (hips for pants, bust for tops)
- The use: a garment worn over layers (jacket, coat) often requires going up a size compared to the bare chest measurement
For jeans, the inseam length complicates the choice further. An L32 generally fits up to about 1.70 m, while an L34 is suitable beyond that. These guidelines remain indicative depending on body shape and the rise of the jean.
Size 42 today represents a very common build in the French population, far from the “plus size” image it may have conveyed a few decades ago. CNM 2025 data confirms that the average measurements of French women now fall within this range. Thinking in centimeters, comparing each brand’s guides, and considering the material: these three reflexes are enough to avoid most sizing errors when ordering online.
