Use this CO2 calculator to determine dissolved CO2 in your aquarium. The calculator can also be used to calculate recommended bubbles per second of CO2 into the aquarium and a ppm depending on planting level specified. In this case the pH and KH fields can be left blank.
BPS calculations are different for each aquarium and depend on efficiency of diffusion and a number of other parameters. For this reason it it recommended to begin at the lower end of the recommendation, run tests and adjust co2 dosing from there.