What Size Mattress Fits My Room?
Enter your room dimensions below to find out. For most bedrooms, a Queen (60×80") fits rooms 10×10' and up, a King (76×80") needs at least 12×12', and a California King (72×84") is best for taller sleepers in rooms 12×12' or larger. If your room is under 10×10', stick with a Full or Twin.
1Room Dimensions
Pick a common size or enter your exact measurements.
Mattress Size Quick Reference
| Size | Dimensions | Min Room | Best For |
|---|---|---|---|
| Twin | 38" × 75" | 7' × 10' | Kids, single sleepers, bunk beds |
| Twin XL | 38" × 80" | 7' × 10' | Tall single sleepers, college dorms |
| Full (Double) | 54" × 75" | 10' × 10' | Single adults who want space, guest rooms |
| Queen | 60" × 80" | 10' × 10' | Couples (most popular US size), single adults |
| King | 76" × 80" | 12' × 12' | Couples who want room, co-sleeping families |
| Cal King | 72" × 84" | 12' × 12' | Tall sleepers (6'2"+), couples who want length |
A Queen gives each partner 30" of width, the same as a Twin for one person.
A King is equivalent to two Twin XLs pushed together.
Cal King is 4" narrower but 4" longer than a standard King.
Room Size Guides
What size mattress for a 10×10 room?
A 10×10 room fits a Queen (60×80") comfortably with 30" walking space on each side and room for one nightstand. A King will technically fit but leaves only 22" clearance per side — tight but doable if you skip nightstands. Best pick: Queen.
What size mattress for a 10×12 room?
A 10×12 room fits a Queen easily with room for two nightstands and a dresser. A King fits with 22" clearance per side and space for two nightstands. Best pick: Queen with furniture, or King without a dresser.
What size mattress for a 12×12 room?
A 12×12 room fits a King (76×80") comfortably with 30" walking space on each side, two nightstands, and a dresser. This is the standard master bedroom setup. Best pick: King.
What size mattress for a 12×14 room?
A 12×14 room fits a King with room to spare. You can add nightstands, dresser, bench at the foot, and still have generous clearance. Consider a Cal King if the tallest sleeper is over 6'2". Best pick: King or Cal King.
What size mattress for a small bedroom?
If your room is under 10×10', a Full (54×75") or Twin XL (38×80") is your best bet. A Full fits single adults who want more width. A Twin XL works for tall single sleepers. Below 8×10', go with a Twin.
What size mattress for a couple?
A Queen (60×80") is the minimum comfortable size for two adults. A King (76×80") is significantly better — each person gets 38" of personal width, equal to sleeping solo on a Twin. If your room is 12×12' or larger, get the King.
What size mattress for a guest room?
A Queen (60×80") is the ideal guest room size — it accommodates couples visiting while fitting most rooms. If the guest room is small (under 10×10'), a Full (54×75") works fine.
Frequently Asked Questions
What size mattress do I need for my room?
Measure your room's length and width. Subtract 24–30 inches on each side of the bed for walking clearance, plus space for furniture. The largest mattress that fits with those clearances is your answer. Use our calculator above for an exact recommendation.
What is the most popular mattress size?
Queen (60×80") is the most popular mattress size in the United States. It fits rooms as small as 10×10' and gives couples 30" of personal width each.
Will a King mattress fit in a 10×12 room?
Yes, but it's snug. A King (76×80") in a 10' wide room leaves 22" of walking space per side — functional but tight. You'll likely need to skip nightstands or use wall-mounted shelves. A Queen fits more comfortably in this room.
What's the difference between a King and California King?
A King is 76" wide × 80" long. A Cal King is 72" wide × 84" long — 4 inches narrower but 4 inches longer. Choose Cal King if the tallest sleeper is over 6'2" and you value legroom over width.
How much space do I need around a bed?
At minimum, 24 inches of walking space on each accessible side and at the foot. 30 inches is more comfortable and lets you open dresser drawers. If you have nightstands, the space between the nightstand and the wall should be at least 18 inches.
Can I fit a Queen in a 9×10 room?
Technically yes — a Queen (60×80") against the 9' wall leaves 24" per side. But there's no room for nightstands, and foot-of-bed clearance is minimal. Consider a Full (54×75") for more breathing room in a 9×10' space.
What size mattress for a couple in a small room?
If your room is under 10×10', a Full (54×75") is the most practical option for two people, though it's tight at only 27" per person. A Queen is strongly recommended if you can fit it. A Full is the smallest size suitable for two adults.
Do I need to account for a bed frame in my room measurements?
Yes. A bed frame typically adds 2–4 inches on each side and 4–6 inches in length to the mattress dimensions. A headboard adds another 2–6 inches in depth. Our calculator accounts for this automatically.
What if I have an oddly-shaped room?
Measure the rectangular area where the bed will go, ignoring alcoves, dormers, or L-shaped extensions unless the bed will be placed there. Use those measurements in our calculator.
Is a Twin XL the same length as a Queen?
Yes. Both Twin XL and Queen are 80 inches long. The difference is width: Twin XL is 38" wide (one person), Queen is 60" wide (two people). Two Twin XL mattresses side by side equal a King.