Enter your tank volume to see a very rough starting estimate of stocking capacity, based on the commonly cited "one inch of adult fish per gallon" beginner rule of thumb.
This is a rough estimate only, not a real bio-load calculation. Actual safe stocking depends heavily on species, adult size, temperament, swimming behaviour and your filtration - some species need far more space than this rule suggests, and some fish should not be mixed regardless of available "space". Always research individual species compatibility before stocking a tank.
Not sure of your tank's volume? Use our Aquarium Volume Calculator first. See our Setting Up an Aquarium guide and browse fish adverts on The Aviary Hub.