Bowfront Tank Volume
length × width × height × 1.06 ÷ 231. Enter your measurements for gallons and liters.
Volume
28.05 gal
Liters
106.2 L
This is the full water volume; actual capacity is a bit lower once you add substrate, rocks and the fill line.
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The bowfront formula
Volume in US gallons is length × width × height × 1.06 ÷ 231, with every measurement in inches. The 231 is fixed: a US gallon is exactly 231 cubic inches, so cubic inches divided by 231 is gallons, and gallons × 3.785 is liters.
Measuring it without inflating the number
Use the flat back panel for length and the depth at the ends (not the centre bulge) for width. The 6 percent uplift in the formula covers the bow; measuring the centre depth instead double-counts it.
What this shape does to your stocking limit
The bow adds a few gallons and a wider viewing angle over a flat-front tank with the same footprint. It also bends light, so fish near the front look larger than they are, which is how people talk themselves into overstocking.
Standard sizes in this shape family
Nominal gallons and the real footprint they ship with.
- 5 gallon tank16" × 8" × 10.5"
- 10 gallon tank20" × 10" × 12"
- 20 gallon tank24" × 12" × 16"
- 29 gallon tank30" × 12" × 18"
- 40 gallon tank36" × 18" × 16"
- 55 gallon tank48" × 13" × 21"
- 75 gallon tank48" × 18" × 21"
- 90 gallon tank48" × 18" × 24"
- 125 gallon tank72" × 18" × 21"
Volume by tank shape
- Rectangular tankslength × width × height ÷ 231
- Cube tanksedge³ ÷ 231
- Cylinder tanksπ × (diameter ÷ 2)² × height ÷ 231
- Hexagonal tanks(3√3 ÷ 2) × edge² × height ÷ 231
What to do with the number
- What bioload actually isGallons is the denominator, not the answer
- Cycle the tank firstFishless cycling, step by step
Frequently asked questions
How do you calculate the volume of a bowfront tank?
length × width × height × 1.06 ÷ 231, with every dimension in inches. Dividing cubic inches by 231 gives US gallons.
How do I measure a bowfront tank correctly?
Use the flat back panel for length and the depth at the ends (not the centre bulge) for width. The 6 percent uplift in the formula covers the bow; measuring the centre depth instead double-counts it.
Does tank shape change how many fish I can keep?
The bow adds a few gallons and a wider viewing angle over a flat-front tank with the same footprint. It also bends light, so fish near the front look larger than they are, which is how people talk themselves into overstocking.
Keep going with the same pet
Got your gallons? Check how many fish that really supports.
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How much to feed: daily calories and cups by weight, activity and life stage.
Bioload-based stocking guidance, not the oversimplified 1-inch-per-gallon rule.