What type of tub are you removing? If it's cast iron you can remove it by breaking it apart with a sledge hammer and removing it in pieces small enough to handle. If it's steel it shouldn't be too heavy to carry out the door.
Might want to get out your trusty measuring tape and measure your tub. It shouldn't be but five foot long 30-32 inches wide and 15-17 inches deep. Your normal door opening should be 6 1/2 feet high - 30-32" wide. that would give plenty of room for getting a tub through if set on end. Stil the biggest worry is the weight. Is this tub set into an alcove? Do you have three walls surrounding it? One side is finished to the floor - the other sides have a wall coming down to the tub surface.(or is it a claw foot which sits on the floor by itself, oval in shape.) If it's a claw foot, see if a magnet will stick to it and if it's pretty thick . if so it's cast iron and the only easy way to remove it is to break it apart with Mr. Sledge Hammer. Good luck
Most normal tubs will go out a door opening smaller than 30 inches by turning it sideways. Cast iron ones are very strong & heavy, that is why they are good place to go in event of a tornado. Personaly, I would think twice before I removed one if I lived in Tornado alley without a storm shelter. You might be removing the last safe place to go in an emergency.
Removing large cast iron double tubs or whirlpool baths are another matter entirely.
I helped a friend take out a heart shaped cast iron tub once and it nearly kill us going down the stairs.
Glad you did not get killed Bondo!
They had to take ours throught the window we have a 2story house and I guess going down the stairs was not a option lol But I LOVE our new shower,it is a open one and they put in a skylight so it just wakes you up in the morning with the waterfall effect as the water comes out of the wall I guess you could say lol
(Notice I am remodling the entire house lol)
A clawfoot should be taken out by some local reusables fella - they're worth a bit. A steel tub comes out either by removing the drywall around it, or by cutting the bugger in half with a sawzall with a metal cutting blade in it. This is a two-man procedure - one cuts, and the other sprays WD40 at the blade. See if you can beat 3 minutes 44 seconds! Same goes on the no-doubt totally frozen drain on the tub - cut it with the sawzall and then it'll spin like magic.
Tubs are kind of a drag, but usually getting them in and out of the building is far easier than squeazing a 59 3/4 inch tub into a 60 inch spot diagonally... stupid pythagorean theorem!
If you are going to a stand up shower from a tub, then you have drywall and flooring repairs to do, as well as re plumbing.