Should you use numbered or lettered sizing?
Keeping in mind that sizing is relative and that you can only afford to produce a limited number of sizes, how do you decide whether to use numbered (2-16) or lettered (XS-XL) sizes? The cognitive shortcut (pt.2) is to do what brands you aspire to hang with do because you don’t have enough information (pt.2) to make a decision if you’re just starting out. If you think the sizing typical of your market could stand re-working or you just want to do your own thing, you can break the mold if your resources permit the risk. If this describes you, here is some guidance to figuring out which size scale to use.
The difference between the two scales is fit specificity, sales potential, cost savings and price points per size. Here’s a comparison of the two sizing strategies:
Lettered Sizes (XS-XL):
- Fit silhouette is casual and not tightly fitted to the body.
- Sales potential is greater per size since the sizing scale is more generous.
- Cost savings are greater since you’re producing fewer sizes total.
- Prices of lettered sized goods are typically lower than comparative goods with numbered sizes.
Numbered Sizes (2-16 etc):
- Fit is more tightly defined, perhaps even tailored.
- Sales potential per size is less as compared to lettered sizing. If we pretend you’re guaranteed to sell 100 size 2′s and 100 size 4′s, if you offered lettered sizing, you’d sell 200 XS’s.
- Costs are increased as additional size cost more with respect to grading, labels, hang tags and all that.
- Prices are usually higher, numbered sizes are more typically sold at higher price points.
Even so, there are variations depending on circumstances. Here is a such example of how this played out:
A designer wanted to maximize her sales potential by fitting a wider spectrum of customers so she wanted to use XS-L. However, since her niche is clothing for fit, petite women like herself (gymnast/ballerina figures), the fitting profile she envisions is quite specific and runs towards the smaller end of the size spread. Consequently, she thought to design her sizes like so:
I said this wouldn’t do because it would be confusing to consumers. While sizes are relative and can vary quite a bit, they must approach a semblance of the norm. Specifically, her size 8-10 customer would never think to select the size Large even though her size scale works like this. Her size Large would still be a size or two smaller than most other lines’ size Medium. In this case I thought it would be better to use numbered sizes. Since the designer can only afford to develop five sizes at the outset, a bit of negotiation was in order to arrive at her final size spread -which was 2, 4, 6, 8, 10. [It would not be appropriate to criticize this decision. She won't be able to wear her own clothes (at the outset) because she would take a 0 but she's not cutting that size.]
With respect to lettered sizes, keep in mind that these typically encompass two or more sizes. One might describe a size Small as size 2-4 but in reality, it’s a size 4 because it can’t be both. In fact, if one were combining sizes, it would be more honest to say one sold sizes 0, 4, 8, 12 and 16 but that would be very puzzling to shoppers.
The other thing about lettered sizes XS-XL is that there is an increasing expectation that these sizes are more aligned to the weight and size spread of the general population than to a given product line specifically. By that I mean, if you usually wear a Medium, you’ll most often expect to buy a Medium regardless of the brand you buy. The same couldn’t be said about numbered sizes because it is common for a size Medium buyer to wear anything from a 6 to a 12 depending on fabrication, silhouette and all that. Meaning, you’re less likely to get crosswise with consumers if you use numbered sizing for your stuff. The designer in this example would have had a lot of problems if she’d used lettered sizing because the customers who fit the profile of her size Large would typically buy a Small or maybe a Medium in most other brands.
A gentle reminder: Not everyone can afford to launch their line using numbered sizes since it can cost so much more to offer a full size range that will match consumer expectations.
And yes, this deals specifically with adult women’s sizing but it applies equally to men’s and children’s wear.