Bed Size Chart: Mattress Dimensions and the Room Each Size Needs
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Here is every standard US mattress size in one table, with the smallest bedroom each one fits once you leave a 24-inch (60 cm) walkway on both sides and at the foot. Click a size for a room-by-room fit check.
US mattress sizes at a glance
| Size | Mattress (in) | Mattress (cm) | Smallest room with walkways |
|---|---|---|---|
| Twin | 38 × 75 | 97 × 190 | 7.1 × 8.2 ft (≈ 58 sq ft) |
| Twin XL | 38 × 80 | 97 × 203 | 7.1 × 8.6 ft (≈ 61 sq ft) |
| Full | 54 × 75 | 137 × 190 | 8.4 × 8.2 ft (≈ 69 sq ft) |
| Queen | 60 × 80 | 152 × 203 | 8.9 × 8.6 ft (≈ 77 sq ft) |
| King | 76 × 80 | 193 × 203 | 10.3 × 8.6 ft (≈ 89 sq ft) |
| California King | 72 × 84 | 183 × 213 | 9.9 × 9.0 ft (≈ 89 sq ft) |
Mattress dimensions. A bed frame usually adds 2–6 in to each side, so measure the frame you plan to buy.
Bed size by room size
How we worked out the room size
- Walkway: at least 24 in (60 cm) beside the bed and at the foot so you can walk and make the bed. Designers call 30 in (75 cm) comfortable.
- Centered bed: room width ≥ bed width + 48 in, room length ≥ bed length + 24 in.
- Bed against a wall: you lose one walkway, so a narrower room can work. This is common for twin and full beds in small rooms.
Before you buy
- Measure the room wall to wall, then subtract radiators, door swings and closet doors.
- Check the path in: door width, hallway corners and stairs. Our door fit calculator checks whether a box or frame turns the corner.
- Leave room under the bed for storage: see the under-bed storage calculator.
Checked 2026-11-13. Sources: Casper, Home Depot and RTINGS mattress size guides (all list the same standard sizes); walkway guidance from Wayfair’s bedroom size guide and dimensions.com.
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