What Size is a Full Mattress? Full Size Bed Dimensions Explained

Full size mattresses are ideal for solo adult sleepers. A full size provides decent room to stretch and turn; it’s budget-friendly; and it doesn’t take up much space – but it isn’t so small that you feel like you’re sleeping in a dorm room.

A full mattress measures 54in (4ft 6in) wide by 75in (6ft 3in) long, which is wider than a twin size mattress, but narrower and shorter than a queen. While that offers plenty of wiggle room for a single person and their sprawling pet, a full size bed – also known as a double – may be a little too cozy for a couple to share every night.

In this article, we’ll explore whether a full size mattress is the right choice for you, based on your sleeping arrangements, room size, and budget. We’ll also compare full size with other mattress dimensions to help you work out which is the best choice for you.

How big is a full size mattress?

At 54 x 75in, a full size mattress has a surface area of 3,975 square inches – and is a great fit for a small double bedroom or a guest room.

A full size bed may not offer the luxury of a king size, but at 16in wider than a twin, it doesn’t feel like a bed for a kid. It’s a great size for an adult singleton, because it offers plenty of space to get comfortable and cuddle the dog.

What about full XL size?

Some mattresses and beds are also available in a full XL size, which is the same width as a full but longer, at 80in. This could be the ideal choice if you’re a long-limbed adult solo sleeper, but don’t want to give the entire floor space of your bedroom or studio apartment to a king size bed.

How does full size compare with other mattress sizes?

In the US there are 10 standard mattress sizes, but some are more standard than others. Full size is one of the six core mattress sizes, along with twin, twin XL, full, queen, king and California king. If you’re keen to buy a mattress we’ve reviewed here at Expert Reviews, you have a good chance of finding it in these sizes.

Full XL, mentioned above, is one of the four less widely available non-custom sizes, along with crib, small single and Olympic queen. These may be ideal for particular people and rooms, and don’t usually have to be made to order; but they account for a narrower range of mattresses, bed frames and bedding.

Here’s how all the standard US mattress sizes compare:

*these sizes don’t have to be made to order, but they’re harder to find

What are the main pros and cons of a full mattress?

A full size mattress offers a balance of comfort and compactness, with a neat price tag to match. The key advantages of full size beds include:

• Less expensive than queen and king size mattresses, sometimes significantly less (we’ll have more on pricing below);
• Easier to turn and maneuver than larger mattresses;
• Small enough for a small bedroom, guest room, or studio apartment;
• Small enough to leave plenty of floor space;
• Large enough for a solo sleeper to spread out, or for a larger person to use in comfort;
• Large enough for two children to share, and even for a couple to share if they don’t mind getting cozy;
• Easy and affordable to accessorize with bedding.

However, there are some tradeoffs of which to be aware:

• Too small for some couples, especially those who are restless sleepers;
• Too small for couples to share with pets or kids;
• Not roomy enough for a big display of pillows, if that’s your thing.

Why should I buy a full size mattress?

The right size mattress can improve the quality of your sleep and level of comfort to the degree that choosing the right firmness can. You need enough space – width and length – to be able to move around without too much contact with the edge of the bed.

A twin mattress is too narrow for an adult to get comfortable. A twin XL mattress, at 80in (6ft 8in) long, offers extra legroom for taller teenagers, but at just 38in (3ft 2in) wide, neither the twin nor the twin XL offer much room for you to turn over and stretch out your arms.

The 4ft 6in width of a full size mattress delivers ample space to change position and spread out – and to share the space with your pet when they decide to join you. A full size mattress may also be a better choice than a twin for older teens and young adults.

Then there’s the question of dignity. Even if you’re on the small side and sleep alone, do you really want a twin or twin XL bed in your adult bedroom? Even if you’ve sworn off ever sharing a bed with another human being, you deserve the comfort of an adult bed in your own home.

A full size mattress will suit some couples, too. Full size is a good budget choice if space is at a premium in your bedroom, or you’re just starting out together and prefer to sleep snuggled up. If you’re tall, go for full XL if your chosen mattress is available in that size.

However, do note that a full or full XL mattress only provides each of you with just 26.5in in width, which even the happiest of couples could outgrow fast. A queen or king size mattress offers up plenty more width, allowing you each to move position without disturbing your partner’s sleep. Remember, though, that a queen or king size mattress requires more space and a bigger budget.

How much does a full size mattress cost?

You can save hundreds of dollars by opting for a full size mattress, rather than the same mattress in queen or king size.

For example, the bestselling Purple Mattress costs $1,399 in full size, while the queen size costs $1,499 and king size is a leap up to $1,999.

Casper’s The One all-foam mattress is a little cheaper, at $1,125 for a full size, $1,245 for a queen and $1,745 for a king.

Cheaper still is the Emma Original, at $979 for a full size, and $1,459 for king size. Like most mattress brands, Emma regularly runs discount sales that can save you 50% off your investment.

Remember that you need to buy bedding, too. Fitted sheets are widely available in full size, and they’re cheaper than queen or king size options. Target’s Cotton Blend Sateen Fitted Sheet costs $12 in full size, but $18 in queen and $20 in king size. Further up the scale, Crate & Barrel’s Cozysoft Organic Jersey Bed Sheet Set costs $130 for full size compared with $150 in king size.

All in all, a full size mattress is a budget-friendly choice, as well as being space-efficient and roomy enough to help you sleep like a king, if you sleep alone. For a couple with a big enough bedroom and the budget to stretch, we’d recommend upgrading to a queen or king size mattress.