Closed-Back Caps: What They're Called and Which One Fits You

A cap with no snaps, no strap and no buckle behind your head is a closed-back cap, often called a full cap. It comes in two families, and that's where the names split. A true fitted is bought in one exact numbered size. A stretch fit is closed at the back too, but a stretch sweatband adapts it to your head. Everything else you see on the street has an open back you can adjust.

That one look from behind is the whole answer. No hardware means you buy a size or a size range. Snaps or a strap mean you set the fit yourself. Baseball caps are the number one product type at CapUniverse, a streetwear cap shop out of Germany. They're roughly seven of every ten items we send out, so it pays to know which back you're looking at.

Fitted caps: the closed back you buy in your exact size

A true fitted is a cap with a fully closed back and nothing to open. New Era's own silhouette guide calls the 59FIFTY "the originator of the true fitted". It lists the back as closed and the cap as sold in exact fitted sizes. No slider, no snaps, nothing to adjust.

New Era classes the 59FIFTY as a structured cap, with reinforced front panels that hold its classic shape. The visor is built flat, but you're free to curve it the way you like. The crown is a full crown, tall and broad like the original fitted. One thing to keep straight, though. The same guide lists Original, Split Panel, A-Frame, Low Profile and Retro Crown versions. Their crown heights and panel counts differ. So one crown shape doesn't describe the whole line.

Sizing works in numbers. The 59FIFTY chart starts at cap size 7, for a head circumference of 55.8 cm (22 in). It runs up to cap size 8 at 63.5 cm (25 in). In between sit eighth steps such as 7 1/8, 7 1/4 and 7 3/8, each with its own head circumference. You pick a number, not an S/M/L. New Era also warns that the cm size on the label may not match your head circumference in cm. Trust the tape, not the tag.

Measuring takes a minute, and New Era spells out how:

• Grab a flexible tape measure.
• Start in the middle of your forehead.
• Run it around your head about half an inch (about 1 cm) above your eyebrows and ears, right where the sweatband sits.
• Keep it level and snug, but don't pull it too tight.
• Between two sizes? Round up.

Worth knowing before you commit: a 59FIFTY sits among the ten best-selling single products in our shop. Browse the Fitted Caps, or go straight to the 59FIFTY Caps once your number's on paper.

Stretch fit: the closed-back caps that move with your head

Stretch fit is the second closed-back family, and it's the forgiving one. New Era calls the 39THIRTY its original stretch-fit cap, made for comfort and a sporty, low-profile look. The back is closed, and a patented stretch sweatband takes care of fit and comfort. So the stretch lives in that sweatband. The cap itself isn't made of stretch fabric.

Sizes come as ranges instead of exact numbers. New Era's stretch-fit chart gives S/M, M/L and L/XL, together covering roughly 56.8 to 62.5 cm head circumference. Each size spans a range, not a single measurement. Two people with different head sizes can share one size. That's the trade-off. You gain comfort and a margin for error. You give up the one-number precision of a true fitted.

The build is its own thing too. New Era classes the 39THIRTY as a structured cap with a fully curved visor that needs no break-in. Its contoured crown is rounded and keeps the shape smooth from front to back. The guide also names M-Crown, Infinity and M-Crown A-Frame versions. Their crown depth and visor curvature differ, so check the model, not just the family.

Flexfit plays in the same lane. Flexfit (Yupoong) describes its original cap as stretchable. Its woven sweatband of polyurethane and spandex is meant to give you more fit options and more comfort. One caveat: Flexfit's own technology page doesn't use the words "closed back". So go by the caps tagged as closed at the back in our shop, not by the brand name alone.

Our shop's numbers back the comfort argument. Among single products over the last 90 days, a 39THIRTY is the highest placed cap of all. It sits at rank 2 overall, and the only product above it is a bandana. If stretch fit sounds like your thing, the 39THIRTY Caps are the shortcut.

Snapback, strapback and adjustable: how open backs give themselves away

Turn any cap around and the back tells you everything. A row of snaps means snapback. A strap with a buckle or a slider means strapback. No snaps, no strap and no slider means you're holding a closed-back cap.

New Era lists the 9FIFTY back as snapback or strapback: an open back that adjusts with either closure. That little word "or" matters. Calling the 9FIFTY simply "the snapback" is wrong, because it comes in both versions.

The 9FORTY sits right next to it. New Era pairs a classic structured build and a pre-curved visor with a comfortable fit you can adjust. The back is listed simply as open and adjustable. No single closure type is named there. So don't expect every 9FORTY to use a strap, snaps or velcro.

Across its silhouette pages New Era labels the whole line-up by fit type. 59FIFTY is Fitted. 39THIRTY is Stretch Fit. 9FIFTY, 9TWENTY, 9FORTY, 9SEVENTY, 19TWENTY and Casual Classic are Adjustable. That grid covers New Era's own models. It says nothing about other brands, so don't apply those labels to caps from other makers.

New Era is the strongest outside cap brand in our shop. It's rank 2 of all brands by units over the last 90 days, behind only our own CapUniverse label. That's why the fit-type grid is worth keeping in your head. Open backs live in Snapback Caps and Strapback Caps, and the full range sits under New Era.

Picking your closed-back cap: a quick decision guide

Here's the deal: the back of the cap decides how much control you keep. Run through these four lines and you know which family to shop.

• You know your head circumference and want one clean, locked-in fit: true fitted, so a 59FIFTY. Between two sizes, round up.
• You want a closed back without the tape measure drama: stretch fit, so a 39THIRTY in S/M, M/L or L/XL.
• You swap caps with your crew: go open back, snapback or strapback.
• Your hair volume changes, or you pull the cap over a hood: open back again, because you can let it out.

One more thing, because closure and brim get mixed up all the time. Flat brim or curved brim is a separate decision from open or closed. A fitted can go either way, since New Era says its flat visor can be curved as you like. Want the broader map of shapes first? Our cap styles overview walks through the families. The baseball cap versus flat cap comparison covers the silhouette next door.

FAQ: closed-back caps

What are caps with a closed back called?

They're called closed-back caps, often also full caps. They come in two families. A true fitted has no closure at all and comes in one numbered size. A stretch fit is closed at the back too. It comes in size ranges, and a stretch sweatband adapts it to your head.

How do I find my fitted cap size?

Measure your head with a flexible tape measure. New Era says to start mid-forehead and run the tape around your head. It should sit about half an inch (about 1 cm) above your eyebrows and ears, where the sweatband sits. Keep it level and snug, but don't pull it too tight. Between two sizes? Round up.

What's the difference between a true fitted and a stretch fit?

Both are closed at the back. A true fitted is sold in one exact numbered size, so it fits one head circumference. A stretch fit is sold in ranges such as S/M, M/L and L/XL, and a patented stretch sweatband does the rest. The stretch sits in that sweatband, not in the whole cap.

Is a 9FIFTY a snapback or a strapback?

New Era lists the 9FIFTY back as snapback or strapback, so it comes in both versions. Calling every 9FIFTY a snapback is wrong. Check the back of the exact model before you buy.

Can I wear a closed-back cap with long hair or a bun?

You can, but a closed back has no closure you could let out. An open back with snaps or a strap gives you that room. A snapback or strapback is the safer pick if your hair volume changes.