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How to size label your clothing range – letters vs numbers

Selecting the correct size label for your clothing range and whether you use letters or numbers sends a clear message about the market you aim to enter.

Their use isn’t based on random selection.  Both letters and numbers are used to communicate very different things in the industry.

In regards to sampling size selection, this too should be based on who you hope to appeal to within your market sector. Are they teenagers, thirty-somethings or a much older customer?

Whoever they may be, your ideal target market will inform the decisions you make for your brand.

Universal Lettering vs Numerical Size Labels

In apparel there are two standard labelling size ranges to choose from, depending on your market:

  • Letters – XS, S, M, L, XL, XXL are more universal. It is a more generic way of labelling and it is usually suited to less fitted garments.
  • Numeric – The Numeric system of size labels relates to a more personalised approach to sizing. Garments that are more fitted will be labelled with size labels.
  • Numerical size labelling follows different conventions. In Europe, the numeric system is related to actual measurements and size numbers such as 30, 32, 34, 36, 38, 40, 42.

In the United States, their size range starts with  0 and follows with 2, 4, 6, 8 etc.

In the UK the sizing convention usually starts with size 8 and continues with 10, 12,14,16…etc

Below is a graph illustrating how the numerical sizes correspond to one another:

International Clothing Size Chart

UK                                EUROPE                         UNITED STATES & CANADA
10                                   38                                       6
12                                   40                                       8
14                                  42                                       10
16                                   44                                       12
18                                   46                                       14


Many new designers assume that choosing between the two options of numerical v letters is a simple preference, but there is an important reason behind the choice.

The difference between these two standards is all in the grading.

Pattern grading is the process of turning sample size patterns into additional sizes by using a size specification sheet or grading increments. This can be done manually or digitally using computerized pattern cutting software.

Ask Dessy: In how many varieties, colours & sizes should you launch your brand?

Grading of patterns can be general or more tailored and specific. How you label your garment reflects this.

General standard grading for Numerical Sizes:

  • Sizes 00 – 10: 2.5 cm (1”) circumference increase at the bust, waist, and hip measurements.
  • Sizes 10 upwards: 3.9 cm (1.5”) circumference increase at the bust, waist, and hip measurements.

General standard grading for Lettered sizing:

  • Size P – L: 5 cm (2”) circumference increase at the bust, waist, and hip measurements.
  • Size L upwards: 7.6 cm (3”) circumference increase at the bust, waist, and hip measurements.

Lettered sizing covers a wide range of sizes such as:

XS =0-2       •       S = 4-6       •       M = 8-10      •       L = 10-12       •       XL = 12-14

As you can see there is a difference between the two choices.

Deciding which method will work best for your product should not be a decision taken lightly.  Instead, it should be based on the following:

Branding and Market Choices

What do you want your customer’s perception of your brand to be?

If you’re promising a high-end product with a superior fit and higher price point then you should choose the numerical sizing system.

As mentioned earlier, this system is more tailored and specific and will convey quality to your customer through its use.

If your products are cheaper then select the more generic lettered sizing system as this allows you to cover more ground with fewer sizes and a cheaper production run.

Style and Fit

Tailored styles are more fitted by design and therefore require less grading differences between sizes.

Using the Numerical sizing system will immediately impart this information to your demographic.

Looser garments, such as tee-shirts, sweatshirts, kaftans, tunics and pants have a more relaxed fit and can, therefore, cover a range of sizes.

Thus, the use of the lettered sizing system makes more sense.


Active and performance wear garments use stretch fabrics and can accommodate a larger size range, so using the lettered sizing system would be more appropriate here.

Heavier coatings would also fall into this category as they would be used for looser fitted garments.


Casual wear with its looser silhouette and more casual aesthetic would be more suited to the lettered sizing system. Formal wear and evening dresses that use the numerical sizing system are perceived to be more expensive.


As you can see even the smallest of details like size labels leave an impression to a discerning shopper about your brand.

General or particular sizing makes online buyers susceptible to either a confident or doubtful outlook towards labels. It might either encourage or discourage them to buy.

Taking even these small elements and details into consideration from the beginning of collection creation is advisable for those serious about their brands.