Fish Stocking Calculator - Free Online Inch Per Gallon Tool

Free online Fish Stocking Calculator. Check if your aquarium is overstocked using the inch-per-gallon rule. No signup required.

in
in
Stocking Level
57%
Understocked
Total: 11.5 inches of fish

About This Tool

### Can I Add More Fish? Adding "just one more fish" is tempting, but overstocking leads to poor water quality, algae blooms, and sick pets. This **Aquarium Stocking Calculator** uses the general "Inch Per Gallon" rule to give you a quick safety check. ### How It Works 1. **Tank Size**: Enter your aquarium volume (e.g., 20 Gallons). 2. **Add Fish**: List your species and their adult size (e.g., Neon Tetra, 1.5 inches). 3. **Check Level**: We sum the total inches of fish and compare it to your volume.

Key Features

  • **Multi-Species List**: Add as many different fish as you have.
  • **Oversize Warning**: Alerts you if the tank is >85% stocked.
  • **Inch-per-Gallon Logic**: Best for small community fish (Tetras, Rasboras, Guppies).
  • **Dynamic Updates**: See the percentage change as you adjust quantities.

Frequently Asked Questions

Is the 1 inch per gallon rule accurate?

It is a decent *guideline* for small, slim-bodied tropical fish. It does NOT apply to heavy waste producers like Goldfish, Cichlids, or Turtles. For those, you need 2-3x more water volume.

What does 'Maxed Out' mean?

Once you hit 85-100% capacity, your filter has to work very hard to keep the water clean. You must be diligent with weekly water changes.

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