How big is a quilt?
How long is a piece of string?
A patchwork quilt can be any size you want it to be: large enough to cover a king-size bed and touch the floor on all sides, or small enough to fit snugly over a tiny doll. There is no rule that a quilt has to be a particular size; they are as big as they need to be.
Personal preference is probably the biggest factor in determining the exact size of the quilt for a particular bed. I like a medium size, small enough to keep from dragging on the floor, large enough to cover the mattress and the edge of the sheets even if they are not tucked in perfectly. Others prefer an eiderdown to sit on the bed top only, and still others like their bedcovers to reach the floor. Bunk beds need an eiderdown size, especially for the top bunk, the trundle beds also need smaller coverings. One quilt will serve as a different type of bedcover on different beds, too. A double-bed quilt will be a full bedcover on a single bed, or just cover the top of a queen size.
Treatment of the quilt’s pillow area can vary too, by going up and over, going under, or stopping at the pillows. Also, the border can go all the way around the quilt or only on three sides with an extra row of blocks at the top.
Unfortunately, there is no such thing as a ‘standard’ size bed, whether it is cot or ‘king. Each manufacturer makes single, double, queen and king-size beds, and some in between, but the sizes vary from company to company. One advantage of making a sampler album is that you can start making blocks while you think about the size quilt you prefer.