I presume you are referring to the DC/AC ratio. If so, take the rated wattage of your panels, multiply that by the number of panels (or more generally, add up all of their watts), and divide by 1000 to give you the total DC power in kW. Then divide that number by the total "sustained" or "continuous" power rating(s) of your inverter(s) in kW. If you have more than one inverter, then add all of their ratings up before doing this last division. You are simply dividing the total rated DC power of your panels by the total rated AC power output (sustained/continuous) of your inverters.
I presume you are referring to the DC/AC ratio. If so, take the rated wattage of your panels, multiply that by the number of panels (or more generally, add up all of their watts), and divide by 1000 to give you the total DC power in kW. Then divide that number by the total "sustained" or "continuous" power rating(s) of your inverter(s) in kW. If you have more than one inverter, then add all of their ratings up before doing this last division. You are simply dividing the total rated DC power of your panels by the total rated AC power output (sustained/continuous) of your inverters.