King Size Sheet & Mattress Dimensions: Everything to Know

While most fitted king-size bed sheets are a standard width of 76 inches and length of 80 inches, the depth dimension can vary significantly. Mattresses themselves have a range of thicknesses, so you need to check your mattress’ depth to ensure the fitted sheet will fit. 

Traditional mattresses usually have a depth of between 10 and 12 inches, while memory foam mattresses can be between 8 and 12 inches. If you invest in a pillow-top mattress or add a pillow-top accessory to your bed, your overall depth may be as much as 14 to 20 inches.

As you shop for king-size bed sheets, you may see sheet sets called “deep pocket” or “extra deep pocket” intended for mattresses with greater depth.

No one likes the feeling of waking up to a fitted sheet that’s come off the mattress, so it’s wise to make sure your fitted sheet is deep enough!

Flat Sheet Dimensions

King-size flat sheets are designed to completely cover the top of the bed and hang over the sides and bottom of the mattress enough to be tucked underneath. Most flat king-size sheets are 108 inches long by 102 inches wide.

Traditional king-size mattresses are 76 inches wide by 80 inches long, with varying depths between 8 and 20 inches. With a generous width and comfortable length for most people, king-size mattresses are ideal for many couples.

If you’re used to a full or queen-size bed and you sleep in a king-size bed for the first time, it may feel enormous by comparison.

When selecting a comforter or duvet for your king-size bed, aim to choose one that’s large enough to overhang the sides of your mattress. Ideally, your comforter will look neat and inviting when your bed is made, while also providing plenty of coverage for you to snuggle under on chilly nights.

It’s common to find a comforter or duvet in two sizes: a smaller size for full and queen beds and a larger size for king and California king-size beds. Most king duvets and king comforters are 94 inches long by 106 inches wide to provide a generous overhang.

Remember that if your mattress has a very deep pocket dimension, you may need to select a larger size of king bedspread.

Do you remember the first time you walked into a hotel room with a king-size bed? It probably felt positively luxurious to lay down and stretch out! 

Many sleepers who are used to smaller full or queen size beds may be intimidated by the size and expense of upgrading to a king-size bed, but once you get used to it you’ll wonder how you ever lived without one.

If you have a larger bedroom or an open, loft-style floor plan, it's easy to incorporate a king-size bed into your home. King-size beds are perfect for couples, for parents who have frequent midnight visits from their little ones and for pet owners who love to snuggle.

You may have a smaller bedroom better suited for a full or queen bed over a king.

Remember that your king-size mattress dimensions won’t necessarily match the dimensions of your bed frame. Many bed frames are even larger than the mattresses themselves.

If a king-size bed will take up most of your bedroom or you live in a smaller studio apartment, you may want to consider a smaller size bed, especially if you live alone. A queen or full-size bed will still provide plenty of space for a solo sleeper to stretch out.

To read more about the dimension size of king-size mattresses and other bed options, review our Mattress Size & Dimension Guide: Width, Length, & Height of Standard Mattresses.

There’s a significant difference in dimensions for California king vs king-size bedding. California king beds are designed to be more comfortable for taller people, so they have a larger length of 84 inches, but they also have a slightly narrower width of 72 inches.

California-king sheets are made to match California-king bed dimensions, so they won’t fit well on a regular king-size bed.

King vs Queen Sheets: Which is Better

King-size mattress dimensions are usually the same length as queen size mattresses, but a king-size bed is usually 16 inches wider than a queen. As you shop, you may notice a price difference between queen and king-size bedding due to the increase of material needed. 

Though you may need to spend a bit more, it’s always a good idea to purchase the appropriate size sheets for your mattress. In most situations, the dimensions and size of king-size sheets are best suited to a king-size bed.

Compare bed sheet sizes in more detail in the Sheet, Quilt, & Blanket Size & Dimension guide. 

These days there are so many different types of mattresses to choose from. Memory foam, traditional innerspring and hybrid mattresses are some of the most common options you’ll encounter.

Environmental and Health Considerations

As you shop, look for mattresses with natural and environmentally friendly materials like organic cotton and pure wool. New memory foam mattress owners often complain about bad smells and “off-gassing” that can interfere with sleep and leave you wondering what sort of hazardous chemicals you’re bringing into your bedroom. 

Select a mattress with good user reviews, made with natural materials and a strong product warranty for the best peace of mind. No matter which type of mattress you choose, make sure your mattress offers the support you need to avoid waking up with aches and pains. 

Investing in a higher quality mattress now will ensure you can enjoy the comfort of your bed for a long time before you need to replace it. 

To learn about the eco-friendly and ultra-comfy materials that went into Parachute’s mattress, explore the Eco Mattress Guide: Everything to Know

Finding the Best King Size Bed Sheets and Bedding

Bring your dream bed into your home with soft, durable and comfortable sheets, blankets and comforters. Linen, percale, brushed cotton, sateen and 100% organic cotton are all fantastic materials to consider.

Learn more about selecting your ideal bedding material with our Guide to Bed Sheets: Choose the Right Fabric & Style for Your Bed. And here’s some further information about the top bedding fabrics:

• Organic Cotton: Know Your Bedding Like a Designer

• Percale: Know Your Bedding Like a Designer

• Brushed Cotton: Know Your Bedding Like a Designer

• Sateen: Know Your Bedding Like a Designer

• Linen: Know Your Bedding Like a Designer

• Down vs Down Alternative: Everything to Know