Getting a military cover to fit correctly isn't a matter of preference—it's a matter of regulation. A cover that sits too high, too low, or tilts off-center doesn't just look sloppy; it can reflect poorly on your presentation during inspections, ceremonies, and daily wear. Whether you're ordering a garrison cap, patrol cap, or dress cover, knowing how to read a cap size chart and how to take an accurate head measurement can save you from the frustration of returns, alterations, and ill-fitting headgear.
This guide walks you through everything you need to know: how to measure your head correctly, how to read a military hat size chart, how sizing translates across different measurement systems, and what to do if your head falls between two sizes. By the end, you'll have the confidence to order the right military cover the first time.
What Is a Cap Size Chart and Why Does It Matter for Military Covers?
A cap size chart is a reference tool that converts your head circumference—measured in inches or centimeters—into a standardized hat size. For civilian headwear, getting the size slightly wrong is a minor inconvenience. For military covers, the stakes are higher.
Military covers are designed to sit at a specific angle and height, and that positioning only works when the cover fits correctly. A size too small creates pressure on the forehead and temples. A size too large causes the cover to drift and require constant adjustment. Using a cap size chart eliminates the guesswork and gives you a precise starting point.
Most cap size charts display sizes in three formats:
- US hat sizes (6⅞, 7, 7⅛, etc.)
- UK hat sizes (similar to US but occasionally differ by ⅛)
- Metric sizes (based on head circumference in centimeters)
Understanding which format your supplier uses—and how to convert between them—is essential before placing an order.
How to Measure Hat Size the Right Way
Accurate measurement is the foundation of using any cap size chart effectively. Here's how to measure hat size with tools you likely already have at home.
What you'll need to measure cap size
- A flexible fabric or paper tape measure (the kind used in sewing)
- A mirror, or a second person to assist
- A pen and notepad
Avoid using a metal measuring tape. Metal tape measures don't flex around the curve of your head, which leads to inaccurate readings.
Step-by-step: How to measure head for cap
- Step 1: Position the tape measure about one inch (2.5 cm) above your eyebrows. This is the widest part of your head and the standard reference point used across virtually every cap size chart.
- Step 2: Wrap the tape horizontally around your head, keeping it level from front to back. The tape should sit just above your ears.
- Step 3: Make sure the tape is snug but not tight. You want it to sit the way a cap or beret would—close to the head without digging in.
- Step 4: Note the measurement where the tape overlaps. Record this number in both inches and centimeters for flexibility when referencing a cap size chart.
- Step 5: Measure twice. Head measurements can vary slightly depending on how the tape is positioned, so taking two readings and averaging them improves accuracy.
Knowing how to measure head for cap size correctly takes less than two minutes, but it can make a significant difference in the final fit of your cover.
How to Read a Military Hat Size Chart
Once you have your measurement, the next step is cross-referencing it with the right cap size chart. Below is a standard military hat size chart covering the most common sizes:
|
Head Circumference (inches) |
Head Circumference (cm) |
US Hat Size |
|
20 ¾ |
52.7 |
6 ⅝ |
|
21 ⅛ |
53.7 |
6 ¾ |
|
21 ½ |
54.6 |
6 ⅞ |
|
21 ⅞ |
55.6 |
7 |
|
22 ¼ |
56.5 |
7 ⅛ |
|
22 ⅝ |
57.5 |
7 ¼ |
|
23 |
58.4 |
7 ⅜ |
|
23 ½ |
59.7 |
7 ½ |
|
23 ⅞ |
60.6 |
7 ⅝ |
|
24 ¼ |
61.6 |
7 ¾ |
|
24 ⅝ |
62.5 |
7 ⅞ |
|
25 |
63.5 |
8 |
This cap size chart covers the majority of adults, with the most common sizes falling between 6⅞ and 7½. If your measurement lands between two sizes on the cap size chart, the general recommendation is to size up—especially for structured military covers that don't have the flexibility of a fitted baseball cap.
How to Measure for a Cap When Your Size Falls Between Two Numbers
Falling between sizes on a cap size chart is more common than most people expect. Head circumferences don't follow neat increments, and a difference of just a few millimeters can put you right in the middle of two options.
Here's how to handle an in-between measurement:
- For structured covers (e.g., dress caps, peaked caps): Always size up. Structured covers have little to no give, and a tight cover can cause headaches over extended wear.
- For soft covers (e.g., patrol caps, garrison caps): Sizing down is sometimes acceptable since soft fabric offers more flexibility and adjustability.
- If adjustable sizing is available: Some patrol caps come with an internal drawstring or Velcro band. In these cases, knowing your measurement still helps, but you have more room to fine-tune the fit.
When learning how to measure a cap that's already in your possession—to compare against a new purchase—measure the interior band from seam to seam and compare it to the circumference data on the cap size chart.
Types of Military Covers and How Sizing Varies Between Them
Not all military covers use the same sizing conventions, and understanding these differences is key to applying the cap size chart correctly.
Garrison Caps (Side Caps)
Garrison caps are folded covers typically worn during dress occasions. They use standard US hat sizes and are almost always sized using a traditional cap size chart. These covers offer minimal adjustability, so precision matters.
Patrol Caps
The Army OCP patrol cap is one of the most commonly worn military covers. Many versions include an internal adjustment system, but they're still produced in sizes (small, medium, large, XL) that correspond to head circumference ranges. Always check the manufacturer's size breakdown and compare it to a specific cap size chart rather than assuming S/M/L sizing is universal.
Dress Covers (peaked caps)
Dress covers—worn by officers and senior NCOs—are fully structured and use precise US hat sizes. Getting the fit wrong on a dress cover is immediately noticeable, which makes referencing a cap size chart particularly important here.
Covers by Branch
Sizing conventions can also vary by branch. The Marine Corps dress cover, for example, is constructed differently than the Army service cap, and the internal dimensions may differ even at the same nominal hat size. Always consult the branch-specific military hat size chart where one is provided by your supplier or the branch's uniform regulations.
Common Mistakes to Avoid When Using a Cap Size Chart
Even with the right tools and a clear cap size chart in front of you, there are a few common errors worth watching for.
- Measuring over hair: A full head of hair—especially longer or thicker hair—can add up to ½ inch to your measurement. Measure as close to the scalp as comfortable, or account for your hair when selecting a size.
- Using the wrong reference point: Measuring too high on the forehead or too low near the ears will give a smaller circumference reading than the actual fitting position of the cover. The one-inch-above-eyebrow rule is the standard used by cap size chart manufacturers for a reason.
- Relying on an old measurement: Head circumference can change with age and weight fluctuation. If it's been more than a few years since you last checked your size, re-measure before consulting a cap size chart for a new cover.
- Ignoring brand-specific sizing: A size 7⅛ from one manufacturer may not fit identically to a 7⅛ from another. Internal construction, materials, and liner thickness all affect the actual fit. Treat the cap size chart as a starting point, not a guarantee.
What to Do If You Can't Find Your Size on a Standard Cap Size Chart
For those with head circumferences that fall outside the standard cap size chart range—typically below 20¾ inches or above 25 inches—there are a few practical options.
Custom orders: Many military uniform suppliers offer custom sizing for covers. You'll need to provide your exact circumference measurement, and in some cases, additional measurements like front-to-back and ear-to-ear width.
Alterations: A properly sized cover can often be taken to a uniform tailor to have the internal band adjusted. This is a common solution for dress covers where an exact size isn't available.
Adjustable sweatbands: Some covers come equipped with adjustable internal bands that can expand or contract up to an inch. These are particularly useful for patrol caps and garrison caps worn in the field.
Frequently Asked Questions
Below are some cap FAQs for you.
What is the most accurate way to measure cap size at home?
Wrap a flexible tape measure one inch above your eyebrows, keeping it level around your head. Record the measurement in inches and centimeters, then match it to a cap size chart. Measuring twice and averaging the results improves accuracy.
How do I measure head for cap size if I don't have a tape measure?
Use a piece of string or a strip of paper to wrap around your head at the correct position, mark where it overlaps, then measure the length against a ruler. Cross-reference the result with a cap size chart to find your size.
Are patrol cap sizes the same as dress cover sizes?
No. Patrol caps often use S/M/L/XL sizing that corresponds to circumference ranges, while dress covers use precise US hat sizes. Always check the specific cap size chart provided by the supplier for the type of cover you're ordering.
Can I use a standard cap size chart for all military branches?
A standard cap size chart covers most sizing needs, but branch-specific covers may have unique construction details that affect fit. Always cross-reference with any branch-specific uniform regulations or supplier sizing guides when available.