Estimate aquarium stocking level, fish count, stocking capacity, bioload, gallons per fish, filtration needs, and water change planning. Use this fish tank stocking calculator for freshwater tanks, saltwater tanks, planted tanks, community aquariums, goldfish tanks, cichlid tanks, nano tanks, and beginner aquarium planning.
Current stocking level:
The calculator compares your fish load against estimated safe stocking capacity for your tank size and setup.
Recommended fish capacity:
Enter average adult fish size and stocking factors to estimate how many similar fish the aquarium may support.
Tank volume from dimensions:
Enter tank length, width, and height to estimate usable water volume after fill level and decor displacement.
Filtration and water changes:
Estimate filter turnover, monthly water change volume, and whether the entered filter flow is near the selected target.
A fish tank stocking calculator helps estimate whether an aquarium is lightly stocked, moderately stocked, heavily stocked, or overstocked.
It can be useful for freshwater community tanks, planted tanks, goldfish tanks, cichlid tanks, saltwater tanks, reef tanks, nano aquariums, and beginner fishkeeping planning.
Your result shows estimated usable tank volume, stocking load, stocking capacity, recommended fish count, stocking percentage, gallons per fish, gallons per inch of fish, filter turnover, required filter flow, water change volume, and a stocking status warning.
It depends on adult fish size, species, bioload, filtration, tank shape, water changes, aggression, oxygen needs, and swimming space. This calculator gives a rough planning estimate.
No. It is only a rough rule for small, peaceful fish. It does not work well for large fish, messy fish, territorial fish, goldfish, cichlids, or very small tanks.
Use expected adult size. Stocking based on juvenile fish size can lead to overstocking as the fish grow.
Tank shape, surface area, filtration, plants, decor, fish behavior, feeding, oxygen, maintenance, and species compatibility can make the safe stocking level different.