Aquarium Tank Volume Calculator
Compute gallons / liters for any fish tank (rectangle, bowfront, cube, cylinder).
Result
Total gallons
19.9 gal
Water volume
17.5 gal
Liters
76 L
Stocking rule
1 inch of fish per gallon (warm water)
About this tool
Pick tank type and type L×W×H (or diameter × height for cylinders). Get US gallons, liters, the substrate weight, and a safe stock-to-water estimate. A direct answer to r/aquariums 'how many gallons is a 20 gallon long' confusion.
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