How do I calculate airconditioning requirements?

There's many factors needed to properly figure your AC load. Square footage, R value of your insulation in walls, ceilings & windows. How many windows are there and do they get direct sun light all day? How hot does it get in the summer were you live? What kinds of heat loads do you have in your home ( oven, stove, computers, etc.) There are some quick square footage formulas available but they can get you in trouble so I don't recommend them. I would call in a expert in to do a proper estimate. If you get a system that's to small, it will run a lot and have a hard time cooling the house. To large is also not good, it will short cycle and not remove the moisture from your house and you'll feel the dampness.

Rule of thumb= 600 square foot per ton of cooling OR 12,000 BTU. Now this is a ruel of thumb and it could vary up and down quite a bit.

Rule of thumb= 600 square foot per ton of cooling OR 12,000 BTU. Now this is a ruel of thumb and it could vary up and down quite a bit.
Thank you for your help I have decided to go to a professional to get help with my house drawings cheers Don