Not sure what size you need?

As a starting point for home units, to calculate the tonnage needed, divide the square footage of your home by 400 BTUs.
Square footage
400 BTUs = Tonnage needed
400 BTUs = Tonnage needed
For example, if your home is 1600 sq. ft., when divided by 400 BTUs, your home would need a 4-ton air conditioning unit.
If your square footage is not easily divisible by 400 BTUs, then round up. For example, if your home is 1800 sq. ft., when divided by 400 BTUs this is 4.5 tons. You must round this up to 5 tons.

