A standard king size bed is 76 inches wide by 80 inches long (about 193 cm by 203 cm).

Quick Scoop

  • In the U.S. and Canada, a regular king (also called an “Eastern king”) is 76" x 80".
  • That gives you roughly the same length as a queen, but 16" more width for extra space.
  • Many guides note this is the widest standard mattress size most people can easily buy and fit in a typical primary bedroom.

Other king-type sizes (for context)

  • California King: 72" x 84" (narrower but longer).
  • Super/European/UK king options have different measurements (for example, UK king is about 60" x 78").

If you’re measuring your room, many layout guides suggest leaving at least about 30" of clear space on the sides and foot of a king bed so the room doesn’t feel cramped.

In simple terms: if you can fit a rectangle 76" by 80" comfortably in your room with walking space around it, you can fit a king size bed.

TL;DR: Standard king size bed = 76" x 80" (193 cm x 203 cm).

Information gathered from public forums or data available on the internet and portrayed here.