Twin vs full mattress: which one should you buy?
Hi, we’re John and Mimi. “Twin or full?” is the question we hear most from parents moving a child out of a toddler bed, families furnishing a guest room, and adults setting up a small bedroom. Both are the same length; the full is just wider. Here’s how to decide, how much room each one needs, and our mattresses in both sizes at today’s prices.
The short answer
- Twin is 38" × 75". The classic single bed for kids, bunk beds, trundles and daybeds.
- Full is 54" × 75". Same length, 16" wider. Also called a double.
- Pick a twin for a younger child, a small or shared room, or any bunk bed, trundle or daybed made for a twin.
- Pick a full for a child or adult who sprawls, a room that can spare the width, or a guest room where two people might stay a night or two.
- Tall, or a dorm? Neither is long enough for many adults over about 6 feet. Look at a Twin XL (38" × 80") instead; see twin vs Twin XL and Twin XL vs full.
Twin vs full dimensions
| Size | Inches (W × L) | Feet | Sleeping surface | Best for |
|---|---|---|---|---|
| Twin | 38" × 75" | 3'2" × 6'3" | 2,850 sq in | Kids, bunk beds, trundles, daybeds, small or shared rooms |
| Full | 54" × 75" | 4'6" × 6'3" | 4,050 sq in | Kids who sprawl, teens, single adults, guest rooms |
| Twin XL (for reference) | 38" × 80" | 3'2" × 6'8" | 3,040 sq in | Tall single sleepers, dorms, adjustable bases |
A full has about 40% more sleeping surface than a twin, all of it in width. Neither one is longer. Every size from twin to California king is in our mattress size chart.
How much room does each one need?
A common rule of thumb is about 2 feet of walking space on each side and at the foot of the bed. With that much clearance:
- Twin: roughly 7'2" wide × 8'3" long of floor (38" + 4' across, 75" + 2' long).
- Full: roughly 8'6" wide × 8'3" long (54" + 4' across, 75" + 2' long).
- Pushed against a wall, as many kids’ beds are, you save about 2 feet of width with either one.
- Two kids sharing a room? Two twins side by side take 76" of width plus walking space; a bunk bed takes the floor of one twin.
Both sizes arrive compressed and rolled in a box, so stairs and doorways are rarely a problem. More on that in how long a mattress in a box takes to expand.
Who should get a twin?
- Younger kids moving up from a crib or toddler bed. A twin fits most kids’ rooms and nearly every kids’ bed frame. Our best mattress for kids guide covers feel and thickness by age.
- Bunk beds, loft beds, trundles and daybeds. Most are built for a twin, and the frame’s label sets the maximum mattress thickness. See best mattress for bunk beds and trundles.
- Small or shared rooms where floor space matters more than width.
- Tight budgets. A twin is usually the least expensive size of any model.
Who should get a full?
- Kids who sprawl, share the bed with a pet, or have a parent reading bedtime stories next to them.
- Tweens and teens under about 6 feet who want a bigger bed they won’t outgrow soon. Taller teens are better off in a Twin XL; see best mattress for teenagers.
- Single adults in a small bedroom or first apartment. Our best full size mattress guide has picks.
- Guest rooms where a couple might stay for a weekend. A full gives two people only about 27" each, so it’s fine for a visit but tight every night. See best mattress for a guest room and, for couples, full vs queen.
Moving up from a twin to a full later
Many families start with a twin and move to a full as a child grows. If you expect that within a few years and the room has the width, buying the full now can save buying twice. If the twin is going on a bunk bed or trundle, buy the twin; a full won’t fit those frames. These are rules of thumb, not hard ages; measure the room and think about the next few years.
Sheets, frames and bases
- Sheets and protectors don’t cross over. A twin sheet is 16" too narrow for a full. Our mattress protectors and the Essentials Bedding Bundle come in both sizes; see do you need a mattress protector.
- Frames must match. Buy the frame or foundation for your exact size. What a foam mattress can sit on is in what to put under a memory foam mattress.
- Want an adjustable base? Our standalone adjustable bases come in Twin XL and full, not regular twin. If a base is in the plan, choose a full or a Twin XL mattress.
Twin vs full mattress prices today
A full usually costs a little more than a twin of the same model. For example, the 8" Daisy is $249 in twin and $309 in full today, and the 10" Rose is $279 and $369. Our mattresses in both sizes, at today’s prices (a dash means that size is sold out today):
| Pick | Best for | Model code | Twin | Full |
|---|---|---|---|---|
| 8" Daisy Firm | Firm, 8" tall, zip-off washable cover | 8BNV-T |
$249 | $309 |
| 8" Gel Comfort Reactive | Firm budget pick for kids’ rooms and guest rooms | 8ESSCA-T |
$259 | $269 |
| 10" Gel Comfort Reactive | Medium firm value for back and side sleepers | 10ESSCA-T |
$269 | $329 |
| 10" Rose Medium | Room to grow for tweens and teens | 10BNV-T |
$279 | $369 |
Prices are today’s prices, read live from our catalog, with free FedEx shipping included. A dash means that model isn’t made in that size.
Want something thicker or a hybrid in a full? Our best full size mattress guide lists every full we carry by price, and the firmness guide explains soft vs medium vs firm.
8" Daisy - Firm Mattress - 8BNV
Our pick for most kids in a twin or full. Firm, a manageable 8" tall, and the cover zips off for the washing machine.
- Firm support for growing kids
- Zip-off washable cover
- Twin and full at today’s prices
From $249 (Twin) · Queen $349 · See sizes & details
10" Rose - Medium Firmness - 10BNV
Moving up to a full? The 10" Rose has a medium feel that suits most tweens, teens and adults.
- Medium feel that suits most sleepers
- Washable zip-off cover
- Twin, full and every other size at today’s prices
From $279 (Twin) · Queen $399 · See sizes & details
Shop this guide
A twin for younger kids, bunks and small rooms; a full for width, teens and guest rooms.
- 8" Daisy - Firm Mattress - 8BNV, from $249. Firm 8" mattress for kids in twin or full.
- 10" Rose - Medium Firmness - 10BNV, from $279. Medium 10" mattress with room to grow.
- Terry Cloth Mattress Protector - MATPROC1, from $31. Waterproof protector in twin and full.
Questions we hear a lot
What is the difference between a twin and a full mattress?
Width. A twin is 38 inches wide and a full is 54 inches wide; both are 75 inches long. A full has about 40 percent more sleeping surface.
Is a twin or a full better for a child?
A twin fits most kids’ rooms, bunk beds, trundles and daybeds, so it is the usual pick for younger children. A full is a good choice for a child who sprawls or a room with space to spare, and it can last into the teen years.
Can two people sleep on a full?
For a night or two, yes, but each person gets only about 27 inches. Couples who share a bed every night are usually happier on a queen or larger. A twin is a one-person bed.
Is a full mattress longer than a twin?
No. Both are 75 inches long. If length is the concern, look at a Twin XL, which is 80 inches long, the same as a queen.
Do twin sheets fit a full mattress?
No. A twin sheet is 16 inches too narrow for a full. Buy sheets and protectors made for your exact size. Questions? Text John at 818-924-3744.
Still deciding? Just ask us
Tell John who the bed is for, how old and tall they are, and the size of the room, and he’ll tell you honestly whether a twin or a full makes more sense. Text or call 818-924-3744, 6 AM to 9 PM Pacific, take the 60-second mattress quiz, or start with our how to choose a mattress checklist. See our Purchase Policy & Warranty for the details.
Written by John & Mimi Venti, MimiJohn. Standard US mattress dimensions; room sizes and ages are rules of thumb; prices are read live from our catalog and update automatically.