June 09, 2021 5 min read

When talking about sleep quality, you’ll typically hear about mattress type, pillow density, or sheet material. But there’s another factor playing into your sleep satisfaction: pillow sizing.

If you didn’t realize that pillow size matters — or that you even had a choice — you’re not alone. Many buy their pillows based solely on the size of their bed. King-size pillows for a king-size bed. Makes sense, right?

For some, this totally works. However, it’s not a rule you need to follow.

Instead, different sizes work best for certain sleeping positions. Are you a side sleeper? There’s a pillow for that. Do you toss and turn? There’s also a pillow for that.

Like most things related to sleep, pillows are about personal preference. Having a few suggestions can go a long way, but it’s ultimately up to what feels best for you.

what is the size of a king size pillow case

What to Look for When Buying a Pillow

Not sure which details are essential when pillow shopping? Worry not! Consider the following traits when deciding which pillows are best for you.

Fill and Height

The most common pillow characteristic people discuss is filling. You’ve probably got an opinion on the type of fill you prefer, whether you know it or not. 

Do hotel pillows drive you nuts? Or do you get a kink in your neck if you don’t have your favorite pillow from home? It’s probably the filling that you notice. 

Filling affects the pillow’s height which plays a significant role in comfort. On top of that, it also affects the pillow’s texture and washability.

  •   Down. If you want fluff, down pillows are your friend. This soft feather filling molds to fit perfectly around your body. Down comes in a range of densities, so reference the fill power for information about the pillow’s height. Remember, down is pricey and may affect those with allergies.
  •   Down alternatives. Synthetic fills, also known as down alternatives, are much more affordable than feather varieties. However, it comes at a cost of its own. Down alternatives don’t have a long lifespan and aren’t as malleable as natural fills. Still, they’re budget-friendly, easily washable, and great for those with sensitivities.
  •   Memory foam. Memory foam pillows provide extra support by molding around the head and neck. This firm, spongy filling assists alignment, relieves pressure, and reduces snoring.


The size of your pillow can greatly impact your sleep quality. If you roll around a lot in your sleep, you may want a larger pillow. Similarly, a Euro square pillow works well as a throw pillow. It may not be your ideal sleeping pillow, but it can provide the perfect support for reading in bed. 

Before you buy a pillow, get familiar with your sleeping habits. We’ll explain more about this shortly.


It’s not just your pillowcases that need washing, but your pillows as well. They collect dust, sweat, and even bugs! The catch is, some are easier to wash than others. 

You can easily toss most synthetic pillows in your laundry machine, but down and memory foam needs a bit extra attention. Some even require dry cleaning! (The same may be true for your designer bedding sets.) 

Make sure you know what you’re getting into by reading the labels before buying a pillow. 

Pillowcase Measurements

pillowcase measurements

It seems like pillowcase measurements should be pretty straightforward — and they are — but there’s more wiggle room than you might have believed. 

Some pillowcases can fit a couple of different-sized pillows within them. If you own pillows of various sizes, it’s essential to know which pillowcases are appropriate for which pillows.

Standard Pillowcase Size

A standard pillowcase size is 20 inches by 26 inches. Of course, this fits standard-sized pillows, but you can also tuck a queen pillow inside. If your pillow is too soft for your liking, this can make it feel firmer. 

The less common super standard pillowcase tacks on an extra two inches to its length. While still too small for king pillows, it easily fits most other sizes.

Queen Size Pillowcase

Add four inches to the standard pillow, and you’ll get a queen-size pillowcase. These pillowcases measure in at 20 inches by 30 inches and solely fit queen pillows.

King Size Pillowcase

King pillows are significantly larger than any other variety. So what is the size of a king-size pillow case? A whopping 20 inches by 36 inches. 

Don’t be discouraged from king pillowcases if you own smaller pillows. There’s still a way to make it work! There may be a bit of an overhang when putting queen pillows in king cases — and a significant one if you use a standard pillow. To combat this, try tucking the excess fabric into itself, so it appears taut.

Choosing a Pillow Based on Bed Size

Comfort is the most crucial factor when choosing a pillow, but let’s be honest — aesthetics matter. Let’s take a closer look at which pillows are best based on mattress size.

Twin/Twin XL

Standard pillows are generally the best option for twin and twin XL mattresses. As this mattress size only comfortably fits one person, only one standard pillow fits well across. 

Need something a bit bigger? If you have a twin or twin XL bed but want a little more headspace, try the two-inch longer super standard pillow.


Two queen pillows fit perfectly on a queen-sized bed. Since standard super standard pillows are only a few inches smaller, a pair of these will also fit appropriately on your mattress. 

Since queen beds fit two people, these bed sets will usually contain two queen-sized pillowcases.

King/California King

King and California king mattresses give you the most wiggle room when it comes to pillow sizes. Unsurprisingly, two king pillows are ideal on these beds, but two queens or three standards also work. 

Like queen bed sets, king and California king sets will come with two matching pillowcases.


Which Pillow Size Is Right for You?

Using an appropriate pillow size for your sleeping habits can significantly affect your sleep quality. Here’s a guide on how to choose the proper size for you.

  •   Back sleeper. Back sleepers will find the most relief from a king-size pillow. Look for a medium-firm memory foam pillow to maintain the proper support all night long.
  •   Stomach sleeper. Stomach sleepers require a flat pillow to ensure the neck stays in a neutral position. The best size for you? A standard pillow.
  •   Side sleeper. For people who like to squish their pillows like side sleepers, standard pillow sizes work best. Opt for something thick and firm, so your ears stay aligned with your shoulders as you sleep.
  •   Moving sleeper. Are you all over the place when you sleep? If so, a queen or king-sized pillow is ideal for you. A larger pillow stays in place best while you roll around. You’ll need a filling that’s comfortable in all positions. Memory foam or another medium-firm pillow are great options.

Final Thoughts

The standard pillowcase size is 20 inches by 26 inches and can fit standard, super standard, and some queen pillows inside. When it comes to king pillows, you’ll want to get the accompanying pillowcase to ensure a proper fit.