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Slacks vs Dress Pants vs Trousers: Are They the Same?

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David has been covering men's style and grooming topics for The Adult Man as a writer and photographer since 2020. We asked David to sum himself up in four sentences, and here it is. Serial learner. Aspiring wordsmith. Bourbon enthusiast. Jack of some trades. Read full bio.


Last Updated: Feb 23, 2024
19 min read
Evolution of slacks from 18th century to 21st century
Key Takeaways

Today, slacks, dress pants, and trousers all refer to the same broad style of formal pants that you’d wear with a suit jacket or button-down shirt. Previously, however, slacks and dress pants differed slightly in their form and function, and the term “trousers” was a blanket term for pants that was favored by people from the UK.

For most guys, getting out of the awkward stages of adolescence and young adulthood is hard enough. 

Growth spurts, raging acne breakouts, and relationship drama created more than enough to worry about—no need to throw in learning something like how to properly dress for formal events. 

And so, every time you have a wedding, fancy dinner, or otherwise formal event to go to, you scramble to purchase some appropriate clothing, only to have your head spin with a seemingly endless selection of men’s dress pants varieties.

For example, are slacks and dress pants the same thing? Or is there an unspoken rule of men’s fashion that dictates when slacks can be worn and when dress pants can’t?

If you’ve pondered these same mysteries of the universe, I’ve got good news for you: there’s not much difference between slacks, dress pants, and trousers these days. 

In this article, I’ve broken down what slacks, dress pants, and trousers are, what they’re not, and provided useful tips and outfit examples for you to put together your next formal outfit with confidence.

Slacks vs Dress Pants vs Trousers: What’s The Difference?

What Are Slacks?

State and Liberty 11

For a basic definition, slacks are men’s formal pants that are typically made from a cotton or wool-blend fabric. I know, that clarifies nothing.

More specifically, slacks are cut to have a loose or slightly tapered fit, and are meant to be worn with blazers, button-down shirts, or other semi-formal men’s garments. 

You’re probably still thinking, “How is that different from dress pants?” and that’s a good question. Ultimately, it’s not different. 

Dress pants can be made from the same cotton or wool-blend fabrics and have a loose or slightly tapered fit. If you Google, “men’s slacks”, 95% of the results will be for dress pants. 

So what gives?

In modern times, slacks and dress pants are largely the same thing. The main difference is that you typically wear slacks with a blazer but not with a suit jacket, and dress pants are typically worn with a suit jacket. Similarly, slacks can more frequently be dressed down than dress pants.

“Slacks” is an older term for loose-fitting, formal men’s pants, and it’s been carried along through the years to basically mean the same thing as dress pants. 

We’ll dive into the history of slacks a little later.

What Are Dress Pants?

JCrew Ludlow suit pants english wool brown

Dress pants are often made from cotton and wool-blend fabrics, but can also be made from linen, and more recently, polyester. 

While slacks stay safely in the realm of loose-cut to slightly tapered, dress pants can be anywhere from a classic fit to skin-tight, where you’ll need a sturdy pair of pliers to help you get them off.

Most dress pants, though, are more formal than slacks. They often have tapered or slim cuts and are meant to be worn with a matching suit jacket and a button-down shirt underneath. 

That said, when you’re out there in the wild market of men’s formal clothing and come across the pants section, you’re going to see some that are labeled “dress pants” and some that are labeled “slacks.” In today’s fashion landscape, they’re the same thing.

What Are Trousers?

The Adult Man Perk Clothing Feel Good Chinos Grey Legs Crossed

Just when you thought you’d wrapped your brain around the differences between slacks and dress pants, we also need to talk about trousers. 

“Trousers” is a broad term used primarily in the UK and Europe to describe any type of formal or semi-formal pants. Whether they’re tuxedo pants, khakis, chinos, or slacks, in the eyes of the Brits they’re all trousers.

In other words, trousers aren’t something you need to worry about. They’re just another way to say dress pants.

The History of Slacks

18th century man wearing loose fitting slacks

Sources differ on the history of slacks, but there are two prevailing origin stories.

The first claims that the term “slacks” was coined in the 18th century from the Middle English word “slak,” which means loose. The term was applied to loose-fitting pants of the time period, which were notably different from typical men’s pants, which were generally more snug.

Since they were looser and seen to be less formal, slacks were appropriate for sporting events and leisure activities, but not for formal occasions. 

The second origin story comes from a New York Times article titled, “Corporate Etymologies,” in which the author reports that the Haggar Clothing Company worked with an advertiser to come up with the term “slacks”.

This term was also used to describe looser, more casual pants that men wore during leisurely “slack time”, or downtime.  

Whatever the origin, slacks were adopted by the military in the early 20th century, and like many other classic men’s styles, were soon after adopted by the public for everyday fashion.

20th Century British Soldier Wearing Slacks with his uniform

As slacks became more mainstream and fashion evolved, it became more appropriate to wear slacks with a suit and tie, and these casual suits dominated the 50s and 60s.

Today, slacks have fallen under the wide umbrella of men’s dress pants, and most of the time there’s no way to fully distinguish between slacks and other styles of men’s dress pants. 

So, for the rest of this article, any time I say slacks, you can take that to mean dress pants. 

For some of you, that’s likely not a thorough enough definition, given that your local department store still has thirty different-looking options when it comes to choosing formal bottoms. 

That’s what I’ll clear up next.

The 4 Different Types of Slacks and Which Is Best for Your Body Type

Broadly speaking, there are four different types of slacks, and choosing between them comes down to a combination of your body type and style.

Straight Leg Slacks

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These slacks are often listed as having a “regular” or “classic” fit, which is what you’ll most commonly come across while shopping. 

“Straight leg” means that the pants run in a straight, narrow line from the waist to the hem, and don’t taper towards your ankles. These slacks are great for formal events and suits, and are appropriate for every body type.

My favorite straight-leg slacks come from Charles Tyrwhitt. Their Natural Stretch Twill Suit Pants are made with 100% wool and come with a 6 month quality guarantee. 

Charles Tyrwhitt Natural Stretch Twill Suit Trousers

My favorite straight leg pants are the Natural Stretch Twill Suit Pants from Charles Tyrwhitt. These slacks are great for formal events and suits, and are appropriate for every body type. Plus, they're made with 100% wool and come with a 6 month quality guarantee. 

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Tapered Slacks

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As the name suggests, these slacks have a straight leg from the waist to the knee, and then taper slightly to the hem, which gives a more tailored, fitted silhouette. 

Tapered slacks are great for guys with thinner legs, since there’s not as much fabric loosely hanging, but they’re also great for guys with larger legs who want a more snug fit. 

My top pick for tapered slacks are State & Liberty’s Athletic Fit Stretch Suit Pants, which taper down to the ankle for a modern, slick look. These slacks have an athletic fit, which means there’s extra room in the seat and thigh area for muscular and heavier guys.

State & Liberty Stretch Suit Pants

If you ever worry about bending over and having the seat of your pants completely explode, we highly recommend a technical fabric dress pant. If not for your style, at least for your peace of mind. 

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Pleated Slacks

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These slacks feature a series of vertical folds at the waist, which are called pleats. Pleated pants make the waist area look slim while allowing for extra room in the pant legs, which makes these great for guys with bigger legs and midsections. 

Pleated pants have also been having a moment in the fashion limelight, though, which means that if you’re a thinner guy who wants to try out some trending styles, you can wear baggy pleated slacks without looking disheveled. 

My favorite pleated slacks are Suitsupply’s Pleated Vigo Trousers, which capture the classic, elegant, and relaxed style of the 1950’s Italian coastline. 

They’re made from 100% cotton, which makes them breathable and comfy, and feature an off-centered waistband closure and winged side adjusters that bring understated and effortless style.

Suitsupply Light Grey Pleated Vigo Trousers

Suitsupply does their pleated trousers in the Italian style, with many having a draw tab at the sides. They’re a little more “fashion-adventurous,” but that’s exactly what you want for this style of pant. Lighter linen options are ideal for spring and summer, while wool is the go-to for fall and winter.

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Wide Leg Slacks

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Slacks with wide legs are the closest thing to the original form of slacks, before they merged into the amorphous blob of men’s dress pants. 

Since they’re more wide, depending on your body type these can look less formal than slim and tailored dress pant options, especially if you’re on the thin side. 

Guys with legs that could squat a house will probably prefer these, since they have extra room in the seat and legs. 

That said, baggier clothes are trendy these days. If you’re looking to fit in with current fashion trends, pair some wide leg slacks with a tucked-in t-shirt and a pair of sneakers for an outfit that calls back the styles of the 80s and 90s. 

Topman Wide Leg Suit Trousers

With plenty of room in the seat and legs, guys with legs that could squat a house will probably prefer these Wide Leg Suit Trousers from Topman. A neutral hue elevates these seasonless trousers tailored in a wide-leg silhouette that looks smart, whether casual or formal.

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Slacks vs Suit Pants

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One of the most common questions about slacks is whether or not you can wear them as suit pants. The answer is a definite yes. 

When I refer to slacks here, I’m talking about dress pants that are sold by themselves, and not with an accompanying suit jacket. These dress pants can be mixed and matched with a blazer for a more relaxed but still formal vibe. 

Dress pants that come as a set with a suit jacket (a.k.a. suit pants) are generally cut to be more slim than slacks, which gives the suit a more modern, sleek look. 

Baggier styles are in right now, though, so pairing regular cut slacks with an unstructured blazer can bring an effortless, breezy style to any formal outfit.

That said, since the term “slacks” means the same things as “dress pants” these days, you can also get a more tailored pair of slacks and pair them with a blazer and button-down shirt.

My Favorite Slacks to Wear as Suit Pants: 

Best Dress Shirts for Muscular Guys Athletic Model Wearing State Liberty Dress Shirt Playing Pool

When it comes to wearing slacks as suit pants, I have some recommendations.

First, State and Liberty. Although the brand specializes in athletic fit dress shirts, they brought the same principles that make their dress shirts so popular to dress pants, and I’m a big fan. 

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These slacks are made with a nylon, cotton, and spandex performance fabric blend that’s as stretchy as workout pants, but keeps the neat, smooth exterior of dress pants. 

As you’d expect from State and Liberty, they have an athletic cut that provides extra room in the seat and thighs for guys who don’t skip leg day. 

Bluffworks Presidio Blazer and Pants with jacket slung over shoulder
The Bluffworks Presidio Suit

I also recommend Bluffworks’ Presidio and Gramercy Pants, which are both made from 100% polyester fabric that gives the pants moisture-wicking, quick dry, and wrinkle-resistant properties. 

These slacks are great for travel due to the lightweight and stretchy fabric, and they also come equipped with a number of hidden zipper pockets to keep your valuables secure.

Slacks vs Khakis

man wearing khaki Alo Yoga pants

Khakis are likely another subgenre of men’s dress pants that are throwing a wrench in your understanding of men’s dress clothing. 

While khakis fall under the umbrella of men’s dress pants, and therefore slacks, they’re a bit more defined than other dress pants. 

More than anything, the term “khaki” describes the pants’ color, which is that light tan color you’re likely familiar with. Besides the color, khakis are typically made from a heavy, cotton canvas material and have a boxy, loose cut. 

So, khakis are technically slacks and dress pants, but not all dress pants and slacks are khakis.

My Favorite Khakis: 

My top pick for khakis is Everlane’s Midweight Slim Chino Khaki, which is a slightly more casual take on classic khakis, due to being slim cut. However, this gives them some serious versatility with my wardrobe, where they can be paired with both casual and formal outfits.

Everlane Midweight Slim Chino

Featuring two front slant pockets, two back single welt pockets, and button closure at the waist with a zip fly, the Everlane Chino is my favorite khaki pant. The fabric is a breathable cotton weave with a slight 2-way stretch for comfort in motion.

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Slacks vs Chinos

Taft Dragon 3.0 black chinos corduroy jacket2

Similar to khakis, chinos are often considered men’s dress pants, but with a bit of specificity. 

Chinos are defined by their flat-front construction, meaning they don’t have pleats, and cotton twill fabric. This fabric makes these pants lightweight and easy to wear, and they typically taper down to the ankle for a modern, sleek look. 

Chinos are great to wear with casual outfits for first dates and happy hours, but can also be dressed up and worn with a blazer, button-down, and tie. 

So, chinos are technically slacks, by the modern definition, but not all slacks are chinos.

My Favorite Chinos:

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I’m a big fan of Mizzen+Main’s Helmsman Chino Pants. They’re made from a polyester and spandex fabric blend that gives 4-way stretch and the ability to be moisture-wicking and wrinkle-resistant. 

The Helmsman chinos have a slightly more formal look than your average pair, but they’re still easy to dress down with a t-shirt and leather sneakers.

Mizzen+Main Helmsman Chino Pant

These bad boys sit at the top of my list of the best chinos for men. Why? They're durable but don't restrict my movement and they look and fit great. It's not that I'm easy to please, but moreso that chinos that tick all of these boxes are super tough to find.

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Slacks vs Jeans

Man wearing jeans and brown shoes

Slacks and jeans are not at all the same thing, which ought to be refreshing after all the subtle nuances between the different types of men’s dress pants.

Jeans are made from a heavy denim fabric, which doesn’t have the smooth exterior or sheen of slacks. As such, jeans are a casual-wear staple and not intended for formal occasions. 

Some guys argue that jeans can be worn in smart casual outfits, which can be worn in semi-formal settings, but besides that, jeans are meant for casual outings and slacks are for formal events.

My Favorite Jeans:

Revtown slim fit indigo jeans
Rocking my Revtown Jeans over my Thorogood Moc Toes

I’m a big fan of Revtown Jeans. They have a wide selection of classic cuts and jean styles that are made with a combination of denim, spandex, and polyester fabric for unparalleled stretch. 

No more stiff, suffocating denim.

For a premium denim option, I recommend Mott & Bow. Their jeans are made with Italian denim and are constructed with stretch fabric that makes for easy movement and all-day comfort.

Mott & Bow

Just like a quality, well-constructed hoodie, standout jeans will also elevate the appearance of a watch. Mott & Bow makes denim with durable stitching, a lasting build, and fitted cuts that he can style down or up depending on the day.

Shop Mott & Bow Read Our Review

How to Pair Slacks With Your Outfit the Right Way

Pick the Right Pair of Shoes

When it comes to putting an outfit together with slacks, your shoe choice sets the tone and formality of the outfit. If you’re heading to a formal wedding, pair your slacks with oxfords or loafers.

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If you’re going out on the town and want more of a street style aesthetic, go with chunky white sneakers or high-top Converse All-Stars.

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If the occasion calls for more of a smart casual ensemble, wear a pair of leather dress sneakers or suede drivers.

I’m a big fan of M. Gemi’s Feliz Uomo Drivers, which bring classic, effortless style to any outfit. 

M. Gemi Felize Uomo Drivers

M Gemi's best-selling shoe of all time, and for good reason. Each piece is handcrafted in a workshop in Tuscany and features a genuine, hand-stitched suede upper and a soft, leather lining

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If it’s Formal, Wear a Belt

The only exception to this rule is if you have slacks with side adjusters that eliminate the need for a belt, or you’re wearing suspenders. 

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Otherwise, if you’re matching up some slacks with quality dress shoes, you’re going to need a belt, too.

Pick the Right Top

Similar to picking the right pair of shoes, if you’re building an outfit around a pair of slacks for a formal occasion, choose a shirt that matches the occasion. Nine times out of ten, that’s going to be a quality button-down dress shirt or Oxford

model walking toward camera with slacks and shirt from truwear performance brand

If you’ve been in need of a good Oxford for more casual suits and occasions, I recommend Ben Sherman’s Oxford shirts. They come in a wide variety of colors, are made from 100% organic cotton, and have a back pleat that ensures a comfortable, snug fit.

For semi-formal and business casual events, you can always pair slacks with a polo shirt or short-sleeve button-down. 

If you’re going for more of a trendy, streetstyle look, go with a tucked-in, baggy t-shirt, or wear a white tank top and unbuttoned short-sleeve button-down.

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Accessorize Appropriately

Armogan Watches Regalia Silvered White R87 watch face

Accessories can make any plain outfit pop with understated style, and can go a long way in elevating an outfit that’s built around slacks. 

Experiment with different watches, bracelets, rings, and necklaces. 

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When it comes to watches, I’m a big fan of my latest pickup, the Armogan Regalia. It’s a classy chronograph that dresses up or down really easily.

If you’re wearing a blazer with your slacks or a full suit, try adding in a pocket square, a tie bar or cuff links.

Slacks and a blazer make for a great outfit, but if it’s left there it’s unremarkable. Step up your game and create your own unique style with accessories. 

Pick Your Colors Based on the Event and Season

Most slacks come in the typical dark, formal colors of black, charcoal, navy, or dark brown, but you can also come across wild colors and patterns like neon green and pink.

Since you’re not going to show up at a black tie event with a green suit, it’s important to choose the colors of your slacks, shirt, and shoes based on the formality. 

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For formal outings, it’s best to stick with slacks that are black, grey, or dark blue. The season comes into play here as well. If it’s winter or fall, stick with those same colors. 

You can stick with those same colors for spring and summer formal events, or, since it’s likely to be hot, opt for linen slacks with light, neutral colors like cream, taupe, beige, or tan.

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It sounds like a miserable idea to wear dark slacks in the heat of summer, but not if you’re rocking State and Liberty’s Athletic Fit Stretch Suit Pants, which have moisture-wicking and quick-dry properties. 

The polyester and spandex fabric used to make these pants also gives them superior stretch and breathability, so no more stuffy, swampy conditions while you’re dressed to the nines in the summer.

For informal events like going out on the town or garden parties, that’s your time to bust out the fun slack colors and statement pieces, like patterned shirts and unique shoes. 

Slacks Style: Dos and Don’ts

Do:

  • Wear slacks to semi-formal, smart casual, and formal events.
  • Pair slacks with a blazer if the slacks aren’t designated suit pants with a matching suit jacket.
  • Wear a belt when wearing slacks for a formal occasion.
  • Experiment with wearing slacks with sneakers and t-shirts for a trendy, casual outfit.

Don’t:

  • Wear slacks with loud, obnoxious patterns that look tacky and are meant to draw attention.
  • Pair slacks with athletic footwear or shirts of any type.

Conclusion

Business Casual for Men Model Wearing MizzenMain Kennedy Dress Shirt with Slacks

Now that you’ve got a good understanding of what slacks, dress pants, and trousers are and aren’t, shopping for formal clothes shouldn’t be nearly as confusing.

Back in the day there were some slight differences between dress pants and slacks, but as the times and styles evolved, dress pants, slacks, and trousers all represent the same style of men’s formal pants. 

Although slacks are primarily used in formal outfits, they’ve recently broken into trending fashion and streetwear, and you can rock them with sneakers, t-shirts, and even boots.

There’s a wide selection of slack styles and cuts, so keep the purpose of your outfit in mind when you’re putting it together, and refer to the tips above to create a proper slacks outfit.

If you know a guy who tries to bash his head against a wall everytime he shops for men’s dress pants, share this article with him! He’ll thank you when his whole closet is full of slacks for different occasions.

FAQs

Can you wear slacks casually?

You can absolutely wear slacks in casual outfits. Pair slacks with a good pair of leather sneakers, and a baggy t-shirt or sweater, and you’re ready to hit the streets in style.

What qualifies as dress pants?

Dress pants are primarily qualified by the fabric and finish. Most dress pants are made out of cotton, wool, or spandex, and have a smooth, soft finish and feel. Besides that, dress pants always have a front fly, front and back pockets, and a button or clasp waistband closure.

Why are they called slacks?

The term “slacks” was coined by Haggar Clothing Company and their advertising partner, who came up with the name to describe a line of pants that were more loose and casual for leisurely “slack time” or downtime.