Aquarium Stocking Calculator

Worked example

A 120 L aquarium with 10 fish at an estimated 5 g each contains about 50 g of adult biomass. Compare that with your selected 0.75 g/L planning cap.

Assumptions and limits

This is a planning comparison, not a biological stocking recommendation. Species compatibility, adult size, territory, filtration, oxygen, water quality and maintenance matter more than a single biomass figure.

Frequently asked questions

How many fish can I safely keep in my aquarium?

There is no universal fish-per-litre rule. This calculator compares only your inputs with a planning limit you select; research each species and monitor water quality with qualified aquarium guidance.