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Pisces / Aquatics • 4+ Tools

Fish & Aquatics Calculators & Tools

Everyday tools for aquarium hobbyists. Calculate true tank water volume (gallons and liters), substrate displacement, and safe fish stocking limits.

All Fish & Aquatics Calculators (3)

Select a verified tool to calculate nutritional requirements, body mass estimates, growth curves, or reproductive timelines.

conversionsv1.2.0

Aquarium Volume & Fish Stocking Density Calculator

Calculates net water capacity and recommended freshwater fish stocking limits from tank dimensions.

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husbandryv1.0.0

Aquarium Heater Size & Wattage Calculator

Calculate minimum and recommended aquarium heater wattage based on tank water volume and the temperature difference between your room and target aquarium water.

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husbandryv1.0.0

Aquarium Weight & Floor Load Calculator

Calculate total loaded aquarium mass (water, glass tank, substrate, hardscape, and stand) and evaluate residential floor loading pressure in pounds per square foot.

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Scientific & Biological Overview

A healthy fish tank starts with having enough water for your fish to swim and breathe comfortably. Calculating your net water volume after adding gravel and rocks helps you avoid overcrowding and keep your aquarium water crystal clear.

Frequently Asked Questions

How do you calculate aquarium gallons from dimensions?
Multiply tank Length × Width × Height (in inches) and divide by 231 to find exact US liquid gallons.
Why does the “one inch of fish per gallon” rule cause problems?
One large 10-inch fish produces over 50 times more biological waste and requires far more swimming territory than ten 1-inch neon tetras combined. Always consider fish body bulk, not just length.
How much water does gravel and tank decor take up?
A standard 2-inch gravel or sand bed, along with decorative driftwood and stones, typically takes up 10% to 20% of your tank’s total advertised volume.