Mattress size chart and room fit calculator
Leave room to make the bed without climbing over it.
Measure the room wall to wall and tell us about the nightstands and the frame. We will find the largest bed that leaves room to walk around it, or check the bed you already own.
Built from the size charts of Amerisleep, Keck Furniture and Emily Henderson.
By the Sizemaven team. Rules checked against their sources October 2026.
- 1Room lengthMeasure along the floor from baseboard to baseboard. Measure the main rectangle and leave out closets and window bays.
- 2Room widthMeasure the other direction the same way, at floor level.
- 3Nightstand widthMeasure the top from side to side. Leave it empty for a typical 20-inch nightstand.
- 4Dresser depthMeasure from the wall to the front of the drawer handles, since that is what you walk past.
Mattress size chart
Mattress sizes from Amerisleep. Rooms are the smallest where our tool finds the walkways, with two 20-inch nightstands and a headboard frame.
| Bed | Mattress | With headboard frame | Smallest room, comfortable | Smallest room, tight |
|---|---|---|---|---|
| Twin | 38 x 75 in | 42 x 81 in | 9 ft 6 in x 7 ft | 9 ft x 7 ft |
| Twin XL | 38 x 80 in | 42 x 86 in | 10 ft x 7 ft | 9 ft 6 in x 7 ft |
| Full | 54 x 75 in | 58 x 81 in | 10 ft x 9 ft 6 in | 9 ft x 7 ft |
| Queen | 60 x 80 in | 64 x 86 in | 10 ft 6 in x 10 ft | 9 ft 6 in x 9 ft 6 in |
| California king | 72 x 84 in | 76 x 90 in | 12 ft 6 in x 10 ft | 10 ft 6 in x 9 ft 6 in |
| King | 76 x 80 in | 80 x 86 in | 13 ft x 10 ft | 11 ft x 9 ft 6 in |
What size bed fits a 12 x 12 room
A queen is the largest bed that fits a 12 x 12 ft room comfortably. On a frame with a headboard and with two 20-inch nightstands, it leaves 40 inches on each side and 58 inches at the foot.
A king fits too, but tightly: 32 inches on each side, above the 24-inch minimum and under the 36 inches that feels comfortable beside a king. Narrower nightstands, a simple frame or a dresser at the foot change these numbers, so enter your own furniture in the tool above.
| Bed | Walkway each side | At the foot | In a 12 x 12 room |
|---|---|---|---|
| King | 32 in | 58 in | Fits, but tight |
| California king | 34 in | 54 in | Fits, but tight |
| Queen | 40 in | 58 in | Fits comfortably |
| Full | 43 in | 63 in | Fits comfortably |
| Twin XL | 51 in | 58 in | Fits comfortably |
| Twin | 51 in | 63 in | Fits comfortably |
Bed size guides
Questions about beds
How big is a queen bed?
A queen mattress is 60 x 80 inches. The frame usually adds 2 to 5 inches, and a headboard adds a few more inches of length, so plan for about 64 x 86 inches of floor.
What is the difference between a king and a California king?
A king is 76 x 80 inches. A California king is 4 inches narrower and 4 inches longer, at 72 x 84 inches, so it can suit a narrower room.
How much space should be around a bed?
At least 24 inches on each side you use and at the foot, which every design guide we read agrees on. 30 inches feels comfortable for most beds, and 36 inches for a king.
What size bed fits in a 12 x 12 room?
A queen, with about 40 inches on each side when two 20-inch nightstands sit next to it. A king also fits, but with about 32 inches per side, which is tight for a bed that size.
What is the minimum bedroom size?
The US model residential code sets 70 square feet and at least 7 feet in every direction for a habitable room. Your local code may differ, and a twin bed fits a room that size only with one side against a wall.
How we size beds
The rule comes from the charts below, checked October 2026. Brands differ, so check the size chart on the product page before you buy. Read our method