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What’s This About
A single-breasted blazer has one column of buttons and fronts that meet, while a double-breasted blazer has two columns and fronts that overlap.
This guide compares the two styles and shows how to wear each one, such as:
What a blazer is, and how it differs from a sports coat and a suit jacket
Button layouts, including what 6×2, 4×2 and Kent mean
Step-by-step buttoning for one-, two- and three-button jackets
Which occasions suit each style, and where neither belongs
Outfit ideas with shirts, knitwear, trousers and shoes
and many more!
Fit and a cloth suited to the season matter more than the button layout, so try both styles on before you decide.
Key Points
01On a single-breasted blazer, leave the bottom button undone and unfasten the jacket when you sit.
02A double-breasted blazer is usually kept fastened when you stand, including the hidden anchor button inside.
03A double-breasted blazer reads slightly more formal, but neither style meets a black tie dress code.
04A navy single-breasted blazer is the more versatile first choice for most wardrobes.
A single-breasted blazer has one column of buttons and fronts that meet in the middle, while a double-breasted blazer has two columns of buttons and fronts that overlap.
That difference changes how the jacket fastens, how it looks open and closed, and how formal it reads.
This guide explains the differences, how to button each style, and how to choose and wear the one that suits your wardrobe and the occasion.
What is a blazer?
A blazer is a tailored jacket worn with trousers that do not match it, such as grey wool trousers, chinos or jeans.
It is usually dressier than a sports coat, which is often cut in a more textured or patterned cloth, and less formal than a suit jacket, which is worn with matching trousers.
The classic version is a navy jacket, often with metal or contrasting buttons, and it is made in both single- and double-breasted styles.
The word is usually traced to the red boating jackets of the Lady Margaret Boat Club at St John’s College, Cambridge, in the 19th century; a popular story linking it to the crew of HMS Blazer has little contemporary evidence behind it.
The key differences at a glance
Scroll horizontally to see all columns →
| Feature | Single-breasted | Double-breasted |
|---|---|---|
| Front | The two fronts meet at the centre without overlapping. | One front overlaps the other, so the jacket closes off-centre. |
| Buttons | One column, most often of one, two or three buttons. | Two columns, often six buttons with two that fasten (written 6×2) or four with two that fasten (4×2). |
| Usual lapels | Notch lapels, with peak lapels as a dressier option. | Peak lapels, with notch and shawl lapels as less common options. |
| Worn open | Looks neat open or closed. | Usually worn fastened, because the overlapping fronts hang loosely when open. |
| How it reads | Versatile, from casual to business. | A little more formal and more noticeable. |
The single-breasted blazer
Buttons and lapels
A two-button front is the most common single-breasted blazer, and it is the easiest to find.
A three-button front closes higher on the chest and has a slightly older, more traditional look; a three-roll-two front has three buttons, but the lapel rolls past the top one so that only two are meant to fasten.
Single-button blazers are less common and give a deeper opening at the front.
Notch lapels are standard, and peak lapels on a single-breasted blazer look a little dressier.
How to button a single-breasted blazer
The usual convention is to leave the bottom button undone.
1.One button: fasten it when you stand.
2.Two buttons: fasten the top button and leave the bottom one open.
3.Three buttons: fasten the middle button, fasten the top one too if you like, and leave the bottom one open.
4.Three-roll-two: fasten the middle button, which is the higher of the two you can see, and leave the bottom one open.
Unfasten a single-breasted blazer when you sit down, so the fronts do not pull, and fasten it again when you stand.
Cloths and everyday wear
Single-breasted blazers are made in almost every cloth, from navy hopsack and serge to flannel, tweed, linen, cotton and seersucker.
Hopsack and other open weaves suit warm weather, flannel and tweed suit cold weather, and linen and seersucker suit summer.
Because it looks neat open, a single-breasted blazer is easy to wear casually, over an Oxford shirt or a knitted polo with chinos or jeans.
The double-breasted blazer
Button layouts
Double-breasted jackets are described by the number of buttons and how many of them fasten.
A 6×2 jacket has six buttons in two columns of three, and two of them fasten, usually the middle and bottom buttons on the outer column, while the top pair is decorative; it is the most common double-breasted layout.
A 4×2 jacket has four buttons in two columns of two, and both buttons on the outer column fasten, which gives a lower, longer opening than a 6×2.
A 6×1 or 4×1 jacket fastens with a single button; a four-button jacket that fastens at the lower button is often called a “Kent”, after Prince George, Duke of Kent, who wore the style.
Inside, most double-breasted jackets also have a hidden button, sometimes called the jigger or anchor button, which holds the underlap in place.
How to button a double-breasted blazer
1.Fasten the inside anchor button first, so the underlapping front lies flat.
2.On a 6×2 or 4×2 jacket, fasten the higher of the two working buttons; many people leave the lower working button open, and fastening it too is also acceptable.
3.On a 6×1 or 4×1 jacket, fasten the single working button.
4.Keep the jacket fastened while standing, because an open double-breasted jacket has loose fronts that flap.
Many people keep a double-breasted jacket fastened when sitting, although unfastening it for comfort is common.
Cloths and structure
Double-breasted blazers are often made in navy wool with metal or horn buttons, but they also come in flannel, linen, cotton and lighter, less structured cuts.
The overlap adds a layer of cloth across the front, so a double-breasted blazer is often a little warmer than a single-breasted one in the same cloth.
Formality and occasions
Neither style is reserved for formal events, and the cloth, colour and what you wear with the blazer change the formality more than the button layout does.
As a general guide, a double-breasted blazer reads slightly more formal and more noticeable than a single-breasted one in the same cloth.
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| Occasion | Single-breasted | Double-breasted |
|---|---|---|
| Smart casual and weekends | Easy to wear open with chinos, jeans and knitwear. | Works fastened over a knitted polo, roll-neck or Oxford shirt. |
| Business casual offices | A navy or grey blazer with wool trousers and a shirt, with or without a tie. | A navy blazer with grey trousers and a shirt, often with a tie. |
| Weddings and celebrations | Suitable when the couple asks for smart casual or allows jackets and trousers. | Same as single-breasted; check whether the invitation asks for a suit instead. |
| Black tie | Not suitable; black tie asks for a dinner jacket. | Not suitable; a double-breasted dinner jacket is a different garment from a blazer. |
For a dress code that asks for a suit, such as a lounge suit or business formal, a blazer and odd trousers are not a substitute; wear a suit instead, which can be single- or double-breasted.
Our double-breasted suit guide covers the matching-suit version of the style.
Fit and proportion
The fit points are the same for both styles: the shoulders should sit at the edge of your own, the collar should rest on your shirt collar, and the sleeves should show a little shirt cuff.
When fastened, the jacket should close without pulling into an X shape around the button.
A double-breasted blazer needs a closer fit across the front than a single-breasted one, because the overlap shows any looseness or tightness, so try it on fastened before you buy it.
Beyond fit, the choice is a question of the silhouette you like: a double-breasted front draws attention to the chest and shoulders, and a 4×2 or Kent layout has a lower button stance, while a single-breasted front gives a longer, narrower line down the middle.
No build rules out either style, so try both in front of a full-length mirror, and ask a tailor about button position and length if the proportions look wrong.
How to style each blazer
These outfits are starting points; swap any garment for one you own in a similar colour and formality.
Single-breasted outfit ideas
Wear: a navy two-button hopsack blazer, a white Oxford button-down shirt, stone chinos, brown suede loafers and a brown leather belt for a smart casual weekend.
Wear: an olive or brown tweed three-button blazer, a light blue shirt, grey flannel trousers, brown leather Derbies and a knitted wool tie for autumn.
Wear: a beige linen two-button blazer, a navy knitted polo, white cotton trousers and tan leather loafers for a summer lunch.
Double-breasted outfit ideas
Wear: a navy 6×2 wool blazer, a white shirt, a burgundy or navy silk tie, mid-grey wool trousers and black or dark brown leather Oxfords for a business casual office or a formal lunch.
Wear: a navy 6×2 blazer, a cream or grey roll-neck, charcoal wool trousers and black leather Chelsea boots for an autumn evening.
Wear: a lightweight cream or light grey 4×2 blazer, a pale blue knitted polo, navy linen trousers and brown suede loafers for a summer event with a smart casual dress code.
Accessories
A pocket square in cotton, linen or silk suits both styles, and a belt that matches your shoes keeps the outfit tidy.
With a double-breasted blazer, high-rise trousers or trousers with side adjusters avoid a belt buckle showing below the overlap.
Single or double-breasted: which to choose first?
If you are buying one blazer, a navy single-breasted blazer is the more versatile choice, because it looks neat open or closed and works with the widest range of shirts, knitwear and trousers.
A double-breasted blazer is a good second blazer if you like a more formal, structured look and are happy to keep it fastened.
Whichever you choose, fit and a cloth suited to the season will make more difference to how it looks than the button layout.