How Big Is a King Bed?
By Stefan Gheorghe
| Published on 
Stefan Gheorghe Founder/CEO
Stefan Gheorghe is the founder and CEO of Homedit.com. In 2008, he launched the platform out of his passion for interior design and home decoration.
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A standard king mattress measures 76 inches wide by 80 inches long (6 feet 4 inches by 6 feet 8 inches). It’s the largest standard mattress size available, offering ample room for couples, co-sleeping families, or anyone who enjoys extra space. Below is a detailed infographic at king bed dimensions and common variations.
Standard King Bed Frame Dimensions
| Component | Width | Length | Notes |
|---|---|---|---|
| Mattress | 76 inches (6 ft 4 in) | 80 inches (6 ft 8 in) | Standard king mattress |
| Simple Frame | 78–82 inches | 82–85 inches | Platform or metal rail beds, low profile |
| Framed with Headboard | 82+ inches | 85+ inches | Adds bulk depending on design, especially at the headboard |
| With Storage | Varies | Varies | Can increase total size |
King Bed Variants
| Mattress Type | Width | Length | Description |
|---|---|---|---|
| Standard King | 76" | 80" | Most common, fits most master bedrooms |
| California King | 72" | 84" | Narrower and longer — better for taller sleepers |
| Split King | 2 x 38" | 80" | Two twin XL mattresses side by side — great for adjustability |
Measurement Tip
Before buying a king bed:
- Measure your room and check doorway and stair clearance.
- Account for added headboard/footboard sizes.
- Leave at least 2 feet of space around the bed for movement.
The recommended minimum room size for a king bed is 12 feet by 12 feet, ensuring enough space for furniture and comfortable circulation.