
Understanding formality is a cornerstone of dressing well.
Only when you understand that flannel is more casual than worsted, and a derby more casual than an oxford, can you begin to understand the impression clothes create - and how to put appropriate things together.
The basic variables are easy to understand:
- Texture is casual (tweed v worsted)
- Lightness of colour is casual (grey jacket v navy jacket)
- Strength of colour is casual (yellow tie v cream tie)
- Pattern is casual (checks v plains - and anything that interrupts, e.g. patch pockets)
Basically, formal clothes are dark, subtle and sleek. The more going on, the less formal a piece is.

But can we assess the formality of a whole outfit? Can we construct some kind of scale?
A reader asked this question recently, and I think it might be useful to try.
It would enable us to do many things, for example rate each other, and consider that a certain ‘rating’ of formality would be appropriate to a certain event, or certain office.
There will always be many exceptions and caveats, but it would remain a useful (if rough) tool.
Some of the caveats include:
- Many things contribute to the formality of an outfit. We will concentrate on the most important aspects of the most important clothes: the colour and material of the jacket and trousers. But other things can combine to move any outfit up or down the scale.
- How you wear things makes a difference - if something is sloppily made, or doesn’t fit, it is likely to be undermined. We won’t even touch on that.
- Ideas of formality can be culturally specific. Americans see black tie as a quintessential wedding outfit, for example, where Europeans do not.
- Some cultural associations can make things seem more formal. A pinstripe suit, for example, could be seen as more formal because of its association with business, than a plain one. Generally, these associations are recognised enough to be easily taken into consideration.
With those in mind, let’s go.

1-2 Black tie
There are of course more formal things than black tie, but for most people this is as formal as it gets. It is today’s formal evening wear.
A lack of colour and a contrast in textures rather than patterns makes black tie the most subtle and formal of ensembles.
The above example is a particular formal example, given it is worn with a wing collar. But it is soft-shouldered, so not quite 1.1 (the highest rating). I'm going for 1.2.

2-3 Worsted suit
The next most formal outfit is a worsted suit - the traditional business wear of much of the past century, but fast becoming formal wear.
It is formal because it is made in a single cloth of a single colour, and because its worsted yarn (the wool) and finish make it smooth and sleek.
There is huge variation in the category, between plain navy and a loudly checked brown worsted, but we will have to let those slide if we are to keep this scale manageable.
I would probably also allow flannel into this category, given it is likely to be plain and grey, even though it is a woollen not a worsted (and therefore has greater texture).
Above outfit: 2.6. It's a pretty informal colour, but is worn with a tie and formal shoes.

3-4 Smart blazer and trousers
Once the jacket and trousers are of a different material, the outfit is immediately more casual.
But it can still be smart: the classic is a navy blazer (in hopsack or cashmere perhaps) and grey trousers (in contrasting texture, so maybe flannel with the hopsack).
I would allow into this category anything where the materials of the two pieces are relatively subtle and simple. Such as light-grey jacket and dark-green trousers, for instance.
Above: Perhaps a 3.3. Formal because of the tie and handkerchief, only informal element being the texture of the tie.

4-5 Casual suit
This is a relatively broad category in one sense: it takes it every material from tweed to linen to cotton, and every colour and pattern imaginable.
But it is also a narrow category, in that it is rarely employed. Few people wear casual or ‘knockabout’ suits today.
When they do, they belong between the blazer and the tweed jacket…
The cord suit above: 4.3. Has a tie and clean white hank, but tie is wool and shirt is denim.

5-6 Casual jacket, smart trousers
By ‘smart trousers’ read anything except jeans (any very casual, washed chinos perhaps).
So this category includes a brown cashmere jacket with pale flannel trousers, a green herringbone jacket with tan cavalry twills, and lightweight wool jacket with cream linen trousers.
There will be a wide disparity within it, depending again on the strength of colour, prominence of pattern and so on (see list of variables at top). But it is a cohesive category, and one which many more men wear to the office - and find it hard to put together.
Above: The cowboy shirt and lack of tie brings this way down the spectrum, to 5.7.

6-7 Casual jacket, casual trousers
Primarily, stuff with jeans. It might be a tweed bespoke jacket, it might be a washed-cotton RTW jacket (think Boglioli), but the top half is likely to be soft and unstructured, to go with the casualness of the trouser.
I might also allow into this category things like Teba jackets, sweater jackets and so on. The very presence of a jacket rather than knitwear or just a shirt immediately raises an outfit up the scale.
Rating of outfit above: 6.5, given the rough texture of the boots and lack of tie

7-8 Knitwear
Without that jacket, we’re into a large and amorphous last category.
If we assume something is worn over the shirt or T-shirt on top, then this is best thought of as the knitwear category.
It has almost bottomless things below it, down to a T-shirt, shorts and flip flops. But few people care by that point, so we will stop here.
Formality of above: Fairly high at 7.2, given the trim, smart nature of the knitwear and the smartness of the shoes
The primary thing that makes a difference to wear an outfit sits in each category is probably the tie. Wear it with the casual jacket and smart trousers, and you’re immediately at the top of category 5.
And the second is probably shoes. The formality of category 6 is transformed if you wear polished derbies with the jeans rather than beat-up trainers.
These points also demonstrate that the categories could possibly overlap. Adding that tie to category 5 may push you above many things in cat 4.
But the absolute formality of each category. They represent a constant that can be achieved in different ways.
So how would you rate what you're wearing today? And those in your office around you?