Carhartt pants are some of the most searched-for pieces in secondhand clothing, for work and for streetwear. The hard part is that Carhartt has used a lot of fit names and model codes over the years, and a vintage pair rarely fits the way its tag says. This guide explains the fits, the main pant styles, the fabrics and how to size a used pair before you buy.
Quick answer: Loose Fit (called Original Fit on many older tags) is Carhartt's roomiest cut, with a full seat and thigh and a wide leg that goes over boots. Relaxed Fit is a step slimmer and closer to a regular fit. Straight Fit is the trimmest. The famous double-knee B01 is a Loose Fit firm duck pant. For vintage, ignore the tag and compare the measured waist, inseam and rise to a pair you already own.
What is the difference between Carhartt Loose, Relaxed and Straight fit?
Carhartt sorts its pants by how much room they have in the seat and thigh, then by the shape of the leg below the knee. Current tags often combine the two, like "Loose Straight" or "Relaxed Straight."
Loose Fit (Original Fit)
This is the classic Carhartt work cut. Carhartt describes it as sitting at the natural waist with a full seat and thigh and a wide leg opening that fits over work boots. It is the fit behind the B01 double-knee and the B11 work pant, and it is what gives Carhartt its baggy streetwear look. Older labels call it "Original Fit" or "Original Dungaree Fit," and Carhartt later moved to the Loose Fit name. If a vintage tag says Original, treat it as Loose.
Relaxed Fit
Relaxed Fit was added as a slimmer option. It still has room in the hip and thigh but sits a little lower on the waist and has a less exaggerated leg. Some Relaxed styles have a straight leg (like the B324 twill pant) and some taper toward the ankle (like the B17 jean).
Straight Fit
Straight Fit, sometimes labeled Traditional Fit, has the slimmest seat and thigh in the work line. The B18 jean is the common example: heavyweight denim with a slimmer seat and a tapered leg. Pick this if you want Carhartt fabric without the bagginess.
| Fit | Older tag names | Waist | Seat and thigh | Leg | Good for |
|---|---|---|---|---|---|
| Loose | Original Fit, Original Dungaree Fit | Natural waist, high | Full | Wide, fits over boots | Work, knee pads, the baggy look |
| Relaxed | Relaxed Fit | Just below the waist | Roomy | Straight or tapered | Everyday wear |
| Straight | Traditional Fit | At or above the waist | Slim | Straight or tapered | A cleaner, closer fit |
Double-knee vs carpenter vs dungaree: what do the names mean?
These three words describe features, not fits, and one pant can be all three.
- Dungaree: Carhartt's own word for its work pants. The B01, B11 and B324 are all sold as dungarees. It does not mean a specific cut.
- Carpenter: a work pant or jean with tool features, mainly a hammer loop on the left leg and a utility or ruler pocket on the right thigh.
- Double-knee (double-front): a second layer of fabric down the front of each leg. Openings at the bottom of the extra layer let you slide in knee pads and clear out debris.
Which Carhartt pant model codes should you know?
Many Carhartt pants from the late 1990s through the 2010s have a short model code on the tag. Newer pieces often use a six-digit style number instead. These are the codes you will run into most in used Carhartt.
| Code | Style | Fabric | Fit |
|---|---|---|---|
| B01 | Double-front work dungaree | 12 oz firm duck | Loose |
| B136 | Double-front work dungaree | 12 oz washed duck | Loose |
| B11 | Single-front work pant | 12 oz washed duck | Loose |
| B151 | Canvas utility work pant | 7.5 oz canvas | Loose |
| B324 | Twill dungaree | 9.25 oz twill | Relaxed, straight leg |
| B17 | 5-pocket jean | 15 oz denim | Relaxed, tapered leg |
| B18 | 5-pocket jean | 15 oz denim | Straight, tapered leg |
| B13 | Carpenter jean | Denim | Loose (since replaced) |
The B01 is the one people hunt for. The double-front duck pant dates back to 1939, and it has stayed close to the same design since: firm duck, double knees, a hammer loop, tool pockets and a high, roomy cut. Carhartt now sells it as the Iconic B01 under style number 106679, so a short "B01" on the tag points to an older pair.
Duck, canvas, twill or denim: which fabric is which?
The fabric changes how a pair feels, wears and shrinks.
- Firm duck (B01): 12 oz tightly woven cotton canvas. Stiff when new and slow to break in. It fades to the soft, creased look people pay extra for, and it matches a vintage Carhartt Detroit or Active jacket.
- Washed duck (B11, B136): the same 12 oz duck, washed at the factory so it feels softer from day one and shrinks less at home.
- Canvas (B151): a lighter 7.5 oz cotton canvas. Cooler and easier to wear in summer, but less armor-like than duck.
- Twill (B324): 9.25 oz cotton twill with a smoother face, closer to a heavy chino.
- Denim (B17, B18): heavy 15 oz denim on the classic jeans, softer than duck and familiar if you wear Levi's.
If a duck pant feels soft but shows little fading or fraying, check the tag. It may be washed duck rather than a firm duck pair that has been worn in.
How do older Carhartt pants fit compared to new ones?
Vintage Carhartt tends to be cut fuller and higher in the rise than today's Relaxed and Straight styles. A 1990s Original Fit pair sits high on the waist with a big seat and thigh, which is exactly why it drapes and stacks the way streetwear buyers want.
The tag size is where people get burned. Years of washing and drying can shrink cotton duck and denim, so the waist and inseam on an old pair are often smaller than the label. Sizing on new pairs is not perfectly consistent either: reviewers of the B01 often report inseams that run long and waists that run snug. On a used pair, both effects can stack, so it is common to see a vintage Carhartt measure an inch or two off its tag.
One more mix-up: Carhartt WIP is a separate, fashion-focused line with its own sizing. WIP pants are cut slimmer and closer to true size, so a WIP Double Knee will not fit like a mainline B01.
How do you measure Carhartt pants flat?
Button a pair that fits you well, lay it flat and measure:
- Waist: straight across the top of the waistband, edge to edge, then double it.
- Inseam: from the crotch seam down the inside of the leg to the hem.
- Front rise: from the crotch seam up to the top of the waistband. This matters a lot with Carhartt, since Loose Fit sits high.
- Thigh: straight across the leg about an inch below the crotch.
- Leg opening: across the hem, then double it.
Compare those numbers to the listing, not the tag. At ThriftManGuy, every pair is measured flat by hand, and the listing shows the real waist and inseam along with a condition grade of Excellent, Very Good or Good. For more on this method, see how to buy vintage clothes online without guessing your size.
Do Carhartt pants shrink when you wash them?
Yes, a little, and mostly in the first few washes. Carhartt has said its firm duck pants shrink 3 percent or less when washed as directed. Unwashed firm duck shrinks more than pre-washed duck, and hot water and high dryer heat make it worse. A pair that has been washed for years has done most of its shrinking, so its flat measurements are close to what you get.
To keep a used pair the same size:
- Wash inside out in cold or warm water.
- Skip bleach, which weakens cotton and blotches brown duck.
- Hang dry or tumble dry on low.
Our guide on how to wash thrifted vintage clothes has more detail.
FAQ
Is Carhartt Original Fit the same as Loose Fit?
Yes. Original Fit is the older name for Carhartt's roomiest cut, with a high waist, full seat and thigh and a wide leg. Carhartt now calls it Loose Fit.
Do Carhartt double-knee pants run big?
The B01 is cut roomy in the seat and thigh and high in the waist, but the waist itself can run snug and the inseam long. On vintage pairs, go by the measured waist and inseam instead of the tag.
What is the difference between the Carhartt B01 and B11?
Both are Loose Fit 12 oz duck work pants with a hammer loop and tool pockets. The B01 is stiff firm duck with double knees. The B11 is softer washed duck with a single front.
What is the difference between Relaxed Fit and Loose Fit Carhartt?
Loose Fit has the fullest seat and thigh and the widest leg and sits at the natural waist. Relaxed Fit is slimmer and sits a little lower, closer to a regular fit.
How much do Carhartt pants shrink?
Carhartt says firm duck shrinks 3 percent or less when washed as directed. Hot water and high heat add more. Vintage pairs have usually finished shrinking already.
Shop vintage Carhartt pants
We sell one-of-one pieces out of Moorhead, MN, serving Fargo-Moorhead and shipping nationwide. Browse the Carhartt collection, the wider workwear section, all jeans and pants, and Dickies work pants. Every pair is measured flat by hand and graded for condition.