What to consider when buying an air compressor
The air output (CFM) of the compressor will determine the tools that it can power. Add up the CFM requirement of all of the tools that you wish to run off a single compressor at once, then increase this value by a third to find the minimum CFM that you require from your compressor.
Before you buy an air compressor, also consider your pressure (PSI) requirement. A single-stage air compressor, which can attain pressures of up to 150 PSI, is usually suitable for small domestic jobs, while a two-stage air compressor, which can produce between 150 PSI and 200 PSI, is more suitable for home workshop and professional use.
Finally, when choosing a tank size, bear in mind that a small tank will provide pressure in short bursts, while a large tank will provide sustained pressure for far longer.