Levi Strauss & Co. manufactures some of the highest quality jeans in the world. But believe it or not, they weren’t always in the clothing business. When they were founded in 1853, Levi Strauss & Co. was a simple drygoods store. Although it sold denim patches to customers, they never considered garment manufacturing.

That is, until the 1870s, after one of the company’s frequent customers sent a proposal to Levi Strauss himself offering to go into business together manufacturing tough, quality overalls and jeans. Strauss accepted, and in the 1890s Levi’s created the first pair of Levi’s 501 Jeans, a style that not only went on to become the world’s single-most popular article of clothing, but would serve as the flagship for one of the most legendary lines of jeans the world has ever known.

You’ve undoubtedly heard of the 501s and perhaps even the 505s, but what about the rest of Levi’s iconic denim? Also, which pair is right for you? Here’s a complete guide to Levi’s numbers:

501-Levis

501 Original Fit

The original jeans that started it all, the Levi’s 501s were specifically designed and released in the 1890s for hard-working men who needed clothing that could take a beating and stand up to the toughest work environments.

Cut: Straight Leg Classic Fit

Leg Opening: 16”/17”

Best For: Average Joes and working men

502-Levis

502 Regular Taper Fit

The 502 is an in-between for people who enjoy the comfort of the 501s, but also like the fitted look of the 505s. They feature a roomier thigh like a regular 501/505, but with a modern tapered leg for a more casual, modern look.

Cut: Straight Leg Slim Fit

Leg Opening: 14.5”

Best For: The casual kid and the modern worker

504-Levis

504 Regular Straight Fit

The 504 Regular Straights may not have preceded the original 505s in a historical way, but stylistically, the nomenclature is perfectly fitting. The 504s mimic the 505s almost identically in style and fit, only with some modern alterations. The 504s feature a slightly smaller leg opening, a slightly slimmer look (less room in the thighs), and most noticeably sit low on the waist, where the traditional 505s sit at the waist.

Cut: Straight Leg Slim Fit

Leg Opening: 16.25”

Best For: The Modern Classic Rocker

505-Levis

505 Regular Fit

Another staple of the Levi’s family, 505s were first released in 1967 in the midst of a cultural revolution in the U.S. and elsewhere. Featured on the cover of the Rolling Stones’ 1971 album Sticky Fingers, the 505s became a symbol of Levi’s transition from work clothing to a cultural mainstay.

Cut: Straight Leg Loose Fit

Leg Opening: 16.5”

Best For: The Mick Jagger in us all

510-Levis

510 Skinny Fit

A newer addition to the Levi’s lineup, the 510s are skinny fit jeans that are purposefully left leaner, meaner, and with as little leg opening space as possible. Musicians, artists, and athletes all love the style, and since its release a few years ago, it has become a permanent fixture in the Levi’s stable.

Cut: Skinny Leg Slim Fit

Leg Opening: 13” Opening

Best For: Skateboarders and rock and rollers

511-Levis

511 Slim Fit

An offshoot of the 510s, Levi’s 511s are for modern men who follow fashion trends, but aren’t necessarily trying to squeeze into anything. They’re slim and narrow, but not uncomfortable, and they go well with everything from t-shirts and hoodies to loafers and blazers.

Cut: Tapered Leg Slim Fit

Leg Opening: 14.5”

Best For: Fashion-forward men unwilling to sacrifice comfort

512-Levis

512 Slim Tapered Fit

Billed as a generally narrower version of the 511 Slim Fits, the 512 Slim Tapered Fit actually features the smallest leg opening of all in the 510, 511, and 512 class. In fact, it’s narrow the whole way through, from the thigh through the leg opening. Where it does align with the 511 is that it sacrifices zero comfort with its snugger fit. It actually might be a little magical—we have no idea how they do it.

Cut: Tapered Leg Slim Fit

Leg Opening: 12”

Best For: The man who likes it skinny, but not uncomfortable

513-Levis

513 Slim Straight Fit

Another new style from Levi’s, the 513 Slim Straight Fit is exactly what it promises to be—a mid-rise design that sits just below the waist and features a slim seat and thigh, but still promises comfort and on-trend modern style. You can pair ‘em with Chucks and a t-shirt or go all out with something more sleek and modern. A blazer and hoodie combo, maybe?

Cut: Straight Leg Slim Fit

Leg Opening: 15.75”

Best For: Younger professionals

514-Levis

514 Straight Fit

Coming out of the slim seat and thigh models, the 514 Straight Fit still sits below the waist, but offers a regular seat and thigh and features a 16.5” leg opening for a stylish, yet relaxed fit that doesn’t care about “skinny.”

Cut: Straight Leg Regular Fit

Leg Opening: 16.5”

Best For: The Renaissance Man

517-Levis

517 Boot Cut Fit

Boot cut Levi’s are as American as apple pie, and the 517s are an excellent choice if you want classic style with modern touches (like a slightly slimmer leg).

Cut: Boot Cut Slim Fit

Leg Opening: 18.25”

Best For: The Cattle Rancher

519-Levis

519 Extreme Skinny Fit

Even a word as, well, extreme as the word extreme is probably slightly an understatement for the fit on these jeans. Super skinny through the hip and thigh, all the way down through the 12.25-inch leg opening, these jeans are probably more for show than comfort, but damn are they worth it.

Cut: Straight Leg Slim Fit

Leg Opening: 12.25”

Best For: Iggy Pop and literally nobody else

527-Levis

527 Slim Boot Cut Fit

Even if boot cuts aren’t necessarily your style, every man should own at least one pair of 527s because they’re incredibly comfortable and go with everything from sneakers to cowboy boots. They feature the standard boot cut leg opening, but with a slim seat and thigh, which gives them a modern look and feel while maintaining the classic comfort of a solid boot cut.

Cut: Boot Cut Slim Fit

Leg Opening: 18.25”

Best For: The Karaoke Country Boy

541-Levis

541 Athletic Straight

Probably not the most cleverly named of Levi’s lineup, the 541 Athletic Fit features a straight leg and athletic seat and thigh, which means they offer a slimmer look, but nothing stifling. If you’re looking for something to accentuate the features you’ve worked so hard for, without feeling like you’re wrapped in plastic wrap, the 541s are your huckleberry.

Cut: Straight Leg Athletic Fit

Leg Opening: 15.75”

Best For: The Man Who Appreciates Comfort and Leg Day

550-Levis

550 Relaxed Fit

Levi’s 550 Relaxed Fit jeans are probably some of the most comfortable pieces of denim you can lay on your butt. If you’re not into the low rise craze, the 550 Relaxed Fits are meant to be loose and relaxed with a relaxed seat and thigh, but also feature a slight taper down toward the ends, which makes them ideal for use with sneakers, trainers, and even **shudders** sandals, if that’s your thing.

Cut: Tapered Leg Relaxed Fit

Leg Opening: 16.5”

Best For: Average Joes

559-Levis

559 Relaxed Straight Fit

If you’re into the low and easy style of the 550s but want a more modern, below-the-waist fit, the 559 Relaxed Straight Fits are absolutely perfect. Featuring a roomy seat and thigh while paying attention to modern style, the 550s don’t taper (in fact, their 18-inch leg opening is massive), but feel perfect from top to bottom.

Cut: Straight Leg Relaxed Fit

Leg Opening: 18”

Best For: The Astute Man Who Appreciates Style, But Cares About Comfort

560-Levis

560 Comfort Fit

Another creatively titled addition to the family, the 560 Comfort Fits are literally just that—loose fitting, mid rise, and a slight (and completely unobtrusive) taper below the knee to give them some form and make these jeans one of the most comfortable of the Levi’s family. But, the 16-inch leg opening still makes them practical and stylish.

Cut: Tapered Leg Loose Fit

Leg Opening: 16”

Best For: Men who just want to be comfortable

569-Levis

569 Loose Straight Fit

Low, loose, and baggy are the three words that most perfectly describe the 569 Loose Straight Fits. Even though they’re technically a considered a straight leg, they are super wide with an 18.5-inch leg opening. They’re the literal opposite of the 510s, but they aren’t bad in their own right.

Cut: Straight Leg Loose Fit

Leg Opening: 18.5”

Best For: Uhh… People Who Think JNCOs are a Tad Aggressive