Women’s Clothing Sizes Explained

Have you ever wondered what the sizes on American women’s clothing labels really mean? Or why some styles have numbers on their size labels while others have letters? As a brand, creating easy-to-understand, well-fitting sizing for your designs can be a challenge. Use the quick guide below to see the different sizing options, what they mean, and when it makes sense to use one sizing method over another.

Numeric sizing

Numeric women’s sizing is labeled as even numbers (2,4,6,8,10, etc.). Numeric sizing is common for more tailored, luxury, or dressy garments like formal dresses, suit pants, blazers, etc. This is because there is less of a difference between sizes than in other sizing types. With numeric sizing, customers are able to get a very precise fit appropriate for tailored, non-stretchy garments. 

Odd numbered numeric sizing (3,5,7,9, etc.) is reserved for junior’s clothing. The sizes are similar to the even-numbered women’s sizes, but the proportions are different. Juniors sizes are typically less curvy as they are made for younger teens whose bodies are still developing and changing. The style and intended fit is also designed for a younger customer.

Alpha sizing

Alpha sizing (XS, S, M, etc.) is more often used for more casual clothing as there is a bigger jump between sizes. This makes the fit more flexible. Garments that are looser-fitting like a hoodie or swing dress, ones that are very stretchy like leggings or a tee-shirt, or ones that are adjustable like an elastic-waist or wrap skirt are good candidates for alpha sizing. Any single size garment can fit multiple different people whose measurements differ by a few inches up or down. 

There are fewer sizes to develop and produce across an alpha range compared to numeric sizing, making it a cost-effective option for smaller and mass-market brands. There is less inventory to carry with fewer sizes and it isn’t as hard to predict demand with fewer sizes. 

Waist measurement sizing

Less commonly, women’s apparel can be sized by the waist measurement of the wearer’s body (28,29,30,31,32, etc.) as you see in jeans from some brands. The confusing part here is that the number on the size label may or may not actually correspond to the waist measurement of the wearer’s body and probably won’t match the garment waistband measurement either. The measurement of small to middle sizes might match the labeled size more closely than the larger sizes. 

The style of the garment and the fabric also play a part in how close the garment measurement is to the labeled size. A lower-rise pant will have a larger waistband measurement for its labeled size as it is meant to sit lower on the hips. The waist measurement size is the natural waist of the body which is not always where the actual waistband of the pant sits. A very stretchy pant might even measure smaller than the labeled size as it is meant to stretch and expand. 

Plus sizes

Plus sizes can be sized either numeric or alpha just like smaller sizes. Numeric plus sizes often have a ‘W’ after the number that stands for ‘women’ (18W, 20W, 22W, etc.). Plus sizing usually starts anywhere from 14W-20W, though some plus-size exclusive brands go down to a size 10. 

Alpha plus sizes are often actually alpha-numeric and have a sequential number followed by an ‘X’ (2X, 3X, 4X, etc.). Brands will start their alpha plus sizes somewhere between 0X-3X. 

I find there is even more plus size variation between brands when comparing garments labeled as the same size. This is partly because of how each brand decides to transition their sizes from the smaller sizes to the plus sizes. Some brands run XL, XXL, 1X, 2X, 3X, while others do XL, 1X, 2X, 3X, while still others do XL, XXL, 3XL, or other combinations of these sizes. You can see how this makes plus sizing inconsistent and confusing. In the examples above, a size 3X could be 2, 3, or 4 sizes bigger than the XL!

Size ranges

Why break the size range into a smaller, missy range and a larger plus women’s range at all? The break in size ranges has to do with the proportions of the pattern. As the body gets larger, the proportions change. You can’t achieve as good of a fit for the extreme small proportions and the extreme large proportions grading up and down from the same pattern. Pattern grading changes the size of the pattern, but can’t change the proportions and shape of the pattern very effectively. 

It is best to split the pattern into the missy range pattern and a plus range pattern to create a consistent fit across all sizes. A missy range can cover sizes 00-20 of numeric sizes or XXS-XXL of alpha sizes. Plus ranges can cover 14W-40W or 0X to 6X-8X depending on the grade rule. 

There can be overlap between the two ranges. A size 14 from the missy range and a size 14W from the plus range can have the same bust measurement, but other measurements will differ. The plus range usually has a fuller waist, thigh, and bicep compared to the same size in the missy range. Larger brands often have a few overlapping sizes like this to be able to fit the proportions of more customers. Smaller brands usually choose a size to break from the missy to the plus sizing with minimal overlap to simplify the number of sizes or to focus on their unique niche customer.

Curvy, straight, and athletic fits

Beyond the labeled size in the garment, you’ll also see certain fits advertised such as curvy or athletic. This refers to the body shape of the customer the garment was made to best fit. The sort of standard fit is a straight body type, though you’ll rarely see that mentioned in customer-facing marketing or product descriptions. You will see brands advertising curvy sizes or athletic sizes. 

Counter to how it is often used, curvy does not mean plus size. Curvy means a bigger difference between the waist and hip measurement and usually a fuller thigh and bicep measurement as well. Though plus sizes will also have bigger bicep and thigh measurements, the waist of a plus size garment is also bigger. This is the difference between curvy and plus. For the same hip size, plus will have a larger waist compared to the straight size and curvy will have a smaller waist. Curvy body types are more of an hourglass shape with a curvier silhouette. 

Athletic fits are cut to fit a more muscular body. You’ll see this fit in menswear more often, but some brands use it for women’s sizing too. The shoulders, bicep, and thighs will be larger in an athletic fit than the equivalent straight size fit.

Sizing for women’s clothing isn’t as straightforward as labeling a measurement or two. There are many ways to size women’s clothing depending on the type of product, brand, and the target customer body type. Knowing your options will help you choose the best sizing for your brand.