Double bed is a bit of a misnomer because it is.
Double mattress measurements.
Yes full size beds and double beds are the same thing.
Both terms refer to mattresses measuring 54 inches by 75 inches.
A full mattress is 15 wider than a twin bed but the same length.
Double size beds are usually intended for two persons.
Standard bed sizes are based on standard mattress sizes which vary from country to country bed sizes also vary according to the size and degree of ornamentation of the bed frame dimensions and names vary considerably around the world with most countries having their own standards and terminology.
This makes them five inches longer than traditional twin mattresses.
Full size mattress measures 54 width x 75 in length and these are also commonly referred to as standard double sufficient for adults that need more room than what a twin can offer.
If you are in a relationship this may not be the best choice for you as the fit will be exceedingly tight.
Perfect for tall teenagers who need the length of an adult bed without the width twin xl mattresses measure 39 inches wide by 80 inches long.
The double bed term means the bed is large enough to fit two adults snugly even though this size is often chosen as a bed for one adult or teen.