🐠 Aquarium
Fish Tank Size Calculator
Minimum gallons from fish count and adult length, with schooling and beginner buffers.
Fill in a few details and watch the numbers wag into place.
Friendly reminder: ask your vet. These tools are smart guesses, not medical advice. When in doubt, call the professionals who know your pet best.
Frequently asked questions
- What rule does the fish tank size calculator use?
- It applies the common one gallon per inch of adult fish length rule, multiplied by fish count, with extra volume for schooling species and a beginner buffer if selected.
- Is the result the perfect tank or a minimum?
- Treat it as a starting floor. Many aquarists prefer more gallons than the minimum for stability, especially for active or messy fish.
- Why use adult fish length, not current size?
- Fish grow. Stocking for today's size leads to overcrowding later. Look up adult length for each species before you buy.
- Does tank size replace filtration and maintenance?
- No. Pair the gallon target with a filter rated for the volume and a regular water change schedule. Ask a fish-savvy store or vet about species-specific needs.