What is the tonnage on a 30DNR-106AC this is a 35 year old unit

first is that the airhandler or condensing unit outside It is hard to tell tonnage on the airhandler but if you have the model number of the outside unit that can easily be translated if numbers are not available and you are replacing your unit you can go buy the square footage of your house every 500 square feet = a ton so if you have 1500 square feet you would need a 3 ton.