Where do find on the outside A/C condenser what ton it is?

the model numbers will give you this information if you know what the numbers mean...usually the last two or two of the last four numbers will tell you the tonnage....if your model numer is 785993602..then it would be 36000btus or three tons this might be 785990036this would also be 36000btu...tons are 120000 btu each 1 ton 120000 2ton 24000 btu 21/2 ton 30000 btu 3 ton 36000 btu 31/2 tons 42000 btu 4 tons 48000btu 5 tons 60000btu

Where do find on the outside A/C condenser what ton it is?
Doubt it would say as most are not marked anywhere. Tonnage refers to BTU demand, you need about 12,000 BTUs for each 100 square feet. So if you find anything on your unit, more likely inside on the internal unit, as to what the BTU output is, divide by 12,000 and get the tonnage figure.