According to your comment, you are taking the bike for a year long stay. Often, when people travel with a bicycle they use a special travel case designed to hold the bike, usually if they don't own one, they rent one. Renting a case for a whole year isn't feasible, and even if you do own one you would have to store it for a whole year. Old Hippie's suggestion that you obtain a box from a bike store is a good one, most stores will give them to you, and you could look into what they might charge to pack your bike at the same time if you are not certain how to do it. You would be able to measure the box to find out the shipping dimensions, weight isn't a big concern because items of that size are charged according to the volume of the box, not the weight. You could also find out from your airline how much they would charge to bring it with you. When you get there, no need to bother keeping the box or to store it,you can obtain another one from a bike shop there when you come back.
EDIT: I had a thought. How good a bike is it? Unless you have a high end road bike it might cost less to store your bike and buy one when you get there and sell it when you move back to the UK. Just a suggestion which might make your travel plans easier.