Poll to follow. Specify if you use the mattress alone for sleep, or share with one or more persons. Pets don’t count.
King, shared with my husband. I am 5’11" and he is 6’3"–getting a king-sized bed was pretty much the first thing we did when we moved in together.
Queen because my wife is a minimalist. I lobby occasionally for a king but she feels it will be too much in our bedroom. As with most things, she’s probably right.
My wife and I share a bunk bed, which isn’t covered by your choices.
Actually, we have a “California King”.
I voted not covered because I don’t always sleep with somebody. The squeeze is there three to four nights a week depending on schedules. I have a king size mattress which is good bein’ as the both of us are “king size” men. 
My wife and I share a Full size bed.
Yea, sometimes it is cramped (especially now that she is pregnant and has a pillow between her knees). Once we move into a house, we are planning on upgrading to a Queen.
Although technically it’s not a mattress, it’s a futon. Not American-style futon, actual Japanese futon; thinner, so you usually use two, which makes a mat about 4 inches thick total.
What are those sizes in real money?
A queen-sized bed works OK for the two of us.
King TempurPedic for the Ms and me. And the cat.
King for me, the wife and 4 cats.
FYI, Wikipedia has a list of bed sizes. Here are the American dimensions. The extra-long twin size is commonly used in university dormitories, and means that one’s parents need to buy special sheets (although those are easily available).
Twin 97cm × 191cm
Twin Long 99cm × 203cm
Double 137cm × 191cm
Queen 152cm × 203cm
King 193cm × 203cm
CA King 183cm × 213cm
Cheers. I guess I’m a “situation different” then as I have the largest size IKEA does, 180x200.
If you sleep in a bunk bed, go with the mattress size. (i.e. what size sheet do you use with the mattress). Same deal if you’re in a car bed or clown bed or a Murphy bed.
If you’re a twin long, that’s close enough to twin.
If you’re a CA king, that’s close enough to king.
If you’re on a non-standard mattress size like IKEA, go by sheet size or closest match. If you’re in a hamburger bed or heart-shaped bed, then use the last option.
If you’re in a futon, go by closest size. If you sleep on the floor, then you don’t have a mattress, so the poll doesn’t apply to you. Same deal if you sleep in your car. A tatami mat is not a mattress, either. If you sleep on a boxspring, then go by the size of the mattress that would normally go atop them.
If you sometimes share, that’s close enough to “share”. (i.e. it is not “alone”)
Waterbed mattress, super single, shared occasionally. Judging by the sheets I have to buy, it’s slightly smaller than a queen.
Full/alone.
I recently downsized from a queen because I moved into a house and my bedroom is really small and the mattress and desk took up most of the room so now I have a couple of extra feet to move around.
Queen, shared.
We’d love to have a king, but the bedroom’s not big enough. Well, technically, it is big enough, if we didn’t want to have any other furniture in the room.
I’m 190 cm, and a ~ 200 cm bed (which is apparently King size, according to Wiki) is annoyingly short for me (factor in a pillow, and my feet stick out the other end of the bed. My current bed has two 220x90 cm mattresses (probably the most common size for mattresses over 200 cm here in the Netherlands - even at IKEA - and I don’t think they even sell shorter sizes for adult beds).
Our bedroom was barely big enough for a queen, and we were banging our toes against the doors and falling into the dressers. Then we painted and recarpeted, and did some measuring. And went out and bought a king-size bed and put it against the other wall
: : : : :
and then a miracle occurred
: : : : :
and we have about an extra foot of space on either side. :smack:
The room was trying to tell us something. We finally listened.
King, shared.
It’s a bit too big for the room so my side is alongside the wall, but perfect for when the 3 kids want to jump in.