Selecting the correct bed dimensions is a foundational decision that influences both the aesthetic harmony and functional comfort of a bedroom. Whether you are outfitting a spacious master suite or a compact guest room, understanding the specific measurements and practical implications of king single and double bed sizes is essential. This guide provides a detailed breakdown of standard dimensions, room layout strategies, and mattress options to help you make an informed choice.
The standard dimensions for these two popular configurations are distinct and serve different spatial and occupancy needs. A king single bed, also known as a single extra-long, measures approximately 1200mm in width and 2000mm in length. In contrast, a standard double bed, often referred to as a full-size bed, measures roughly 1350mm in width and 1900mm in length. While the double is wider, the king single is significantly longer, a distinction that caters to taller individuals who require extra legroom.
Comparing King Single and Double Dimensions
To visualize the differences and plan your space effectively, comparing the specifications side-by-side is the most efficient approach. The following table outlines the standard metric dimensions for both bed types, providing a clear reference for your planning.

| Bed Type | Width (mm) | Length (mm) | Common Alternative Names |
|---|---|---|---|
| King Single | 1200 | 2000 | Extra Long Single, Super Single |
| Double | 1350 | 1900 | Full Size |
Space Planning and Room Layout
Understanding the physical footprint is only part of the equation; integrating the bed into the room requires careful consideration of circulation space. For a king single bed, you should generally allow a minimum of 600mm of clearance on the sides for easy access and making the bed. Because of its extra length, ensure there is at least 600mm of space at the head of the bed to prevent a cramped feel and allow for a tall headboard.
Double beds present a different spatial challenge due to their greater width. While they occupy less lengthwise space, they require a wider room to maintain a balanced layout. Ideally, leave a minimum of 600mm between the edge of the bed and walls or furniture. In smaller rooms, positioning the bed so the headboard touches a central wall can create a more balanced visual anchor and preserve valuable floor space.
Mattress Compatibility and Comfort
Dimensions dictate comfort, and the right mattress is crucial for spinal support and rest quality. The king single’s extended length is specifically designed to accommodate taller adults, reducing the need to curl up during sleep. Standard sheets and bedding for this size are readily available, making it a practical choice for those who prioritize legroom without the full width of a double.

Conversely, the double bed offers a compromise between space and sociability. The additional width allows for more freedom of movement and is suitable for couples who prefer to sleep close together or for individuals who simply value a wider sleeping surface. When shopping for linens, confirm the mattress depth, as thicker comfort layers can alter the fit of fitted sheets and require deeper pocket options.
Conclusion and Recommendation
Ultimately, the decision between a king single and a double bed hinges on a balance of personal physical requirements and the architectural constraints of your bedroom. If height is your primary concern and floor space is ample, the king single provides an excellent ergonomic solution. For those seeking a shared sleeping area or a more space-efficient arrangement in a moderate-sized room, the double bed remains a timeless and versatile choice.