It’s impossible to know for sure since it depends on a lot of things like: aeration, amount of plants/fish, temperature, pH etc.
That being said, here is how to make a WAG:
Figure that you want to maintain 20 ppm CO2 and this will go away each day.
Then the bottle will last:
D = NW * 1000 / V/20
Where D is the number of days it will last
NW is the net weight of the bottle in grams
V is the volume of your tank in liters.