By American terms what does a double measure?
 

What about a single and a King?

http://www.buzzle.com/articles/bed-sizes-chart.html
See if this helps

Thanks, that was so quick and yes it does answer my question.

yep, a cot to me is a child's bed but may be a single/twin size. not sure. I think the whole world likes to confuse each other!

And don't even mention the different sizes of king size mattresses: Standard King & California King. I have lived in California all my life but I only slept in a double or a twin !!!

He, he, he.
They grow them bigger in California!

I've heard there is a European King which is larger yet?