Suit Fabrics: Understanding Super Numbers

Super 100s, Super 120s, Super 140s… what is this all about?

When looking at suits, jackets, trousers and overcoats these days, many made from pure worsted wool fabrics will likely boast a super number somewhere on the tags. You will find these numbers tend to start at 100 (you can actually go as low as a super , brands simply tend not to advertise the super number on anything lower than a super 100s), and going – in some rare cases – above 200. There is a misconception that a higher super number means higher quality; this is not the case! It simply corresponds to the fineness of the fabric.

Where did super numbers come from?

The super number is a product of the English yarn count system, which is used to rate the fineness of a yarn. The system is quite simple; the higher the super number, the finer the wool. As such, you will find that the higher super numbers make for a lighter and more luxurious feeling fabric, but it is not without consequence.

If you want to learn more about the intricacies of yarn count measuring systems, this article from TextileLearner is quite comprehensive.

Super Numbers Yarn Thickness Chart (thanks to

How do I know which super number I want?

When I think about what fineness I want from my suit/jacket/trousers, I have three go-to questions in my decision making process.

1: How often will it be worn?

An easy rule of thumb is to determine how often you want to wear the garment. The more often you want to wear it, the lower (to a degree) a super number you want. So, if you are buying a business suit that you want to wear several days per week you will be better off with a super number of 100-120. If it will be worn less often – say once or twice a week – you can go for a super 140s or above.

If you wear a high super number garment several days a week, expect to get less life out of it.

2: How much effort do you want to put into maintenance?

Another factor to take into consideration is the amount of time you want to spend caring for your garment. A lower super number will generally require less maintenance; it is sturdier, and will not wrinkle so easily. On the other hand, a higher super number (140s+) will require more care as it will wrinkle faster and need more time to recover between wears.

Note also that it is easier to repair splits and tears in fabrics of a lower super number.

For the more mathematically inclined, Matthew Plotner has an excellent article breaking down how often each super number should ideally be worn.

3: What is the climate you will be wearing it in?

The finer the wool, the lighter it is. This means that a higher super number is going to retain less warmth. If you are in a particularly hot or cold climate, this will influence your decision. Naturally, the easiest way around this is to have specific garments for different seasons; however if you are trying for an all-rounder you will want to find the best point of balance.

Keep in mind that a particularly coarse wool fabric like tweed will have a low super number precisely because the coarseness of it is what makes it so warm for the winter. Also, if you are thinking about buying a summer garment in a high super number you may want to consider linen instead as it will last longer and be cooler on the skin.

Thanks for reading!

Super numbers are an easy and helpful system once you know what they mean. This knowledge will help you in your next purchase decision!

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With content features ranging from appearances on popular menswear hubs (The Rake, StyleForum, Put This On) to French perfume newsletters and university course readings, Sam is a writer, designer and enthusiast in the fields of menswear and fragrance.

8 thoughts on “Suit Fabrics: Understanding Super Numbers

  1. Whilst not an issue of fineness, I think it would be remiss not to mention that Super numbers really aren’t that usefull for judging how warm a fabric will wear. You are much better off considering the weave. For example an openly woven fabric will allow the air to pass through it and circulate more easily. I have a suit in VBC 4 ply that’s so heavy and course that it feels almost like a suit of armour when putting it on, yet it is easily the most comfortable to wear through summer (well as comfortable as can be in our 40 degree Aussie summers …)


    1. A good point Oliver. It is a rather entry level heuristic of mine; I will research further on weaves and expand my horizons and understanding in that aspect.
      Thanks for your comment!


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