Standard Mattress Sizes

Standard Mattress Sizes: What You Need to Know

One of the first questions customers ask when shopping for a new mattress is surprisingly simple: What size mattress do I need?

While mattress sizing in the United States is fairly standardized, there can be small differences between manufacturers—particularly with handmade and specialty mattresses. Understanding the standard dimensions of each mattress size can make it easier to choose the right mattress, bed frame, sheets and accessories for your bedroom.

At Plank & Coil, we carry mattresses made with a variety of natural materials and construction methods. Because materials, construction and intended use vary, mattress depth can differ considerably even when the length and width follow standard U.S. sizing.

Here is a guide to the most common standard mattress sizes in the United States.

Standard U.S. Mattress Sizes at a Glance

Mattress Size	Approximate Dimensions
Crib	28″ × 52″
Twin	38″ × 75″
Twin XL	38″ × 80″
Full / Double	54″ × 75″
Queen	60″ × 80″
King	76″ × 80″
California King	72″ × 84″

These dimensions represent the commonly accepted standard sizes. Actual measurements can vary slightly by manufacturer, especially with mattresses that are handmade or constructed from natural materials.

Crib Mattress Size

Standard crib mattress: approximately 28″ × 52″

Crib mattresses are considerably smaller than adult mattresses and are designed specifically to fit standard full-size cribs.

A crib mattress is also generally much thinner than an adult mattress. This is intentional: a lower profile allows the mattress to meet crib safety requirements and makes it easier for parents to reach the child.

When purchasing a crib mattress, the fit is especially important. A crib mattress should fit snugly within the crib without significant gaps around the edges.

Twin Mattress Size

Twin mattress: approximately 38″ × 75″

The twin mattress is one of the most popular smaller mattress sizes. It is commonly used for:

• Children’s bedrooms
• Guest rooms
• Bunk beds
• Teenagers
• Smaller bedrooms
• Daybeds

A twin mattress provides a comfortable sleeping surface for one person while taking up relatively little floor space.

Twin mattresses are also a popular choice when furnishing children’s rooms because they can remain useful as a child grows.

Twin XL Mattress Size

Twin XL mattress: approximately 38″ × 80″

A Twin XL has the same width as a standard twin but is 5 inches longer.

That extra length makes Twin XL mattresses particularly useful for taller sleepers. Twin XL mattresses are also commonly used in college dormitories and guest rooms.

Two Twin XL mattresses can also be placed side by side to create approximately the same overall dimensions as a king-size mattress.

Full Mattress Size

Full mattress: approximately 54″ × 75″

Also called a double mattress, the full size provides substantially more width than a twin while maintaining the same 75-inch length.

A full mattress is often a good choice for:

• Teenagers
• Single adults
• Guest rooms
• Smaller bedrooms

Although two people can sleep on a full mattress, it provides considerably less personal sleeping space per person than a queen or king.

Queen Mattress Size

Queen mattress: approximately 60″ × 80″

The queen mattress is the most common adult mattress size in the United States and is a popular choice for couples as well as individual sleepers.

At 60 inches wide and 80 inches long, a queen provides a good balance between sleeping space and room size.

For many bedrooms, a queen mattress offers enough space for two adults without requiring the floor area of a king.

King Mattress Size

King mattress: approximately 76″ × 80″

A standard king mattress is approximately 76 inches wide and 80 inches long.

Its generous width makes the king an excellent option for couples who want more personal sleeping space. It can also be particularly useful for families who occasionally share the bed with children or pets.

A king mattress is essentially the equivalent of two Twin XL mattresses placed side by side.

Because a king requires more bedroom space, it is important to measure the room before purchasing the mattress and bed.

California King Mattress Size

California king mattress: approximately 72″ × 84″

The California king is slightly narrower than a standard king but 4 inches longer.

Its 72-inch width and 84-inch length make it an attractive choice for taller sleepers who want additional legroom.

The California king can also work well in long, relatively narrow bedrooms where its proportions may fit the room better than a standard king.

One important consideration is bedding. California king sheets and accessories are not interchangeable with standard king bedding because the dimensions are different.

Mattress Depth: Why Does One Mattress Look So Different From Another?

Mattress depth, sometimes called mattress height or thickness, is not nearly as standardized as mattress length and width.

You may find mattresses ranging from relatively thin profiles to mattresses that are well over a foot thick. This variation is primarily the result of the materials used, the construction of the mattress and the type of sleeper the mattress is designed for.

For example, a youth mattress will often have a shallower profile than an adult mattress. A simple natural latex mattress may also have a different thickness than a multi-layer hybrid mattress containing latex, pocketed coils, wool and other natural materials.

Some of the factors that influence mattress depth include:

Materials

Latex, wool, cotton, horsehair, springs and other materials can all contribute to a mattress’s overall height.

Construction

A basic mattress may use fewer layers, while a more elaborate mattress can contain multiple comfort and support layers.

Intended Sleeper

Mattresses designed for children and young people are often thinner than mattresses designed for adults.

Comfort Preference

A mattress designed to provide substantial cushioning may have a thicker comfort system than a mattress designed for a firmer, more streamlined feel.

Mattress Type

An all-latex mattress, innerspring mattress and latex hybrid can have very different profiles while still being available in exactly the same standard mattress sizes.

Are Handmade Mattresses Standard Size?

Generally, yes. Handmade mattresses are designed to be compatible with standard U.S. bed frames and bedding.

However, because they may be constructed by hand rather than produced on a highly automated manufacturing line, you can sometimes see slight variations in the finished dimensions.

For example, a handmade queen mattress might measure very slightly differently from another manufacturer’s queen mattress. These differences are generally small, and the mattress will still be designed around the standard queen-size footprint.

This is one reason it is useful to check the manufacturer’s exact specifications when purchasing a mattress, especially if you are pairing it with a very precisely fitted bed frame, platform or other furniture.

Don’t Forget the Bed Frame

Choosing the correct mattress size is only part of the equation. Your bed frame, foundation and bedding should all correspond to the mattress size.

For example:

• Twin mattress → Twin frame and Twin sheets
• Twin XL mattress → Twin XL frame and Twin XL sheets
• Queen mattress → Queen frame and Queen sheets
• King mattress → King frame and King sheets
• California king mattress → California king frame and California king sheets

A standard king and California king are different sizes, so their frames and fitted sheets are not interchangeable.

Measure Before You Buy

If you are replacing an existing mattress, measuring your current mattress and bed frame can be helpful—but don’t assume that every mattress with the same size name will have exactly the same dimensions.

This is particularly important when shopping for handmade mattresses, natural mattresses and specialty sleep products.

If you are purchasing a new bed frame at the same time, check the manufacturer’s dimensions for both the mattress and frame before ordering.

Finding the Right Mattress Size

The best mattress size depends on several factors, including the number of sleepers, bedroom size, sleeper height, available floor space and personal comfort preferences.

For a child, a twin may provide years of useful sleeping space. A taller teenager or adult may prefer the additional length of a Twin XL. For couples, a queen is often an efficient use of space, while a king provides significantly more room to spread out.

And for taller sleepers, the extra four inches of a California king can make a meaningful difference.

Whatever size you choose, remember that length and width are relatively standardized, while mattress depth can vary considerably. The construction and materials inside the mattress ultimately determine how thick it will be.

At Plank & Coil, we are happy to help you understand the differences between mattress sizes, materials and construction so you can choose a mattress that fits both your bedroom and the way you sleep.