Does Theory Run Small Or Big? (Read Before You Buy)

Theory blazers run small, but the rest of their clothing is true to size.

Theory is a contemporary clothing brand that is known for its modern and sleek designs. Their suiting and tailored garments in particular are considered the pinnacle of office fashion.

However, there are some general things to keep in mind when shopping for Theory clothing for a happy customer experience.

In this article, we are going to cover Theory sizing issues and how you can get the perfect fit.

How Does Theory Clothing Fit?

theory sizing

Theory clothes fit true to size in most product categories. However, their suits and blazers run one size small.

Theory’s clothing is designed to be flattering and comfortable, with a focus on creating a modern silhouette.

So, how does Theory’s clothing fit? In general, Theory’s clothing runs true to size. However, the brand’s suits have a European cut, which may not appeal to its broader American audience.

So what should you do?

Here’s what I recommend. Take a look at the official size chart on the Theory website. Now, compare your body measurements with it, and if you are buying a suit jacket, go one size larger than what the chart recommends. For pretty much every other product category, you can follow the chart as is.

If you don’t size up when buying a jacket from Theory, you may feel a bit restricted in your movement, especially in the armhole region.

I would also recommend you to check out Theory Outlet, which is a subsidiary of Theory that is much more affordable.

Theory’s clothing is designed to flatter the figure, so even if you are not a perfect fit, the clothing should still look good on you. Of course, everybody is different, so it is always best to look at the product size chart before making your purchase.

The brand offers free returns, so if you are not happy with the fit of your clothing, you can always return it for a full refund.

Quick Tip 👉 Sometimes the Theory website shows discounts on products only after going through the clearance section and not if you directly go to the product page. Thus, make sure that you always check for your product in the sale section on the Theory website.

What size should you get at Theory?

If you are buying casual clothing, you should go for your true size at Theory. If you are buying dressy or business clothing, make sure to size up.

Other than that Theory also has some Tall sizes, but I personally don’t have a lot of experience with them so I can’t comment about that.

Which Theory Items Run Small?

Theory ClothingSizing
Shirts and TopsTrue to size.
DressesTrue to size.
Suits and BlazersRun small.
PantsTrue to size.

Shirts and Tops

Theory tops are true to size for both men and women. While they have a bigger collection of women’s clothing, they’ve slowly been upping their game in the men’s section too.

Theory’s polo shirts, in particular, are my go-to business casual shirts. Their fit is immaculate, and they last a long, long time.


The answer really depends on the specific dress. Some styles definitely run small, while others are true to size.

This is because it is very difficult to nail the fit of a dress due to the large number of body types out there. However, I still recommend that you go true to size when purchasing your first dress from Theory.

Suits and Blazers

Theory suits and blazers run slightly small on most people due to their European cut. Therefore, I recommend that you size up. For example, if you are normally a size 5, you might want to try a size 6 in Theory suiting.


Theory pants run true to size for both men and women. Their size chart is also pretty accurate in this department, so I recommend going over it before making a purchase.

This is especially true for women’s sizes, where you need to measure a lot more stuff and room for sizing error is smaller.

Theory Size Chart For Women

All measurements are in inches.

Tops and Jackets



2827″ -28″34″-35″

Theory Size Chart For Men

All measurements are in inches.

XS36R34″-36″33″. 33.5″
M40R38″-40″34″- 34.5″

Does Theory make plus-size clothing?

Yes, Theory offers plus-size clothing. The brand’s sizing goes up to a size 20 in women’s clothing, which is considered plus size.

Plus size clothing is generally defined as any clothing size above a size 14. Theory’s plus-size clothing is designed to fit and flatter the curves of plus-size women. The brand offers a variety of styles in plus sizes, from casual to formal wear.

There aren’t a lot of officewear brands that pay so much attention to getting their sizing right, and this makes Theory stand out.

Final Remarks

Since its inception in 1997, Theory has become a market leader in formal clothing for both men and women.

Apart from a wide range of cuts and designs, the brand has managed to achieve this feat by paying close attention to its sizing.

Here’s a quick recap about Theory’s sizing.

While suit jackets and sport coats run small at Theory (for both men and women), the rest of their clothing is true to size.