AC tonnage calculator
One ton of cooling = 12000 BTUS and is designed to cool approximately 400 square feet of living space.
So, if you have a 2000 square foot home you might have one 5 ton unit or two units a 2 and a 3 ton.
These are rough numbers so your results may vary. When your home was built someone (hopefully) did a calculation to determine what size unit to put on that particular home. If the home was made of glass then obviously the unit would be sized larger, for example. I live in a 3200 square foot home but get by with a 3 ton split and a 3.5 The hardest thing for any motor, and I don't care if it is your lawn mower, car, ceiling fan or A/C unit is to turn on. The amp draw of an electric motor is higher at start up to overcome the torque necessary to get up to speed. Example, my compressor will momentarily draw 60+ amps at start up and then run at 14 amps. That is a lot of heat in a short amount of time and motors HATE heat. It is their Achilles heel.
Last how can you tell