An aquarium volume calculator for a bowfront tank converts inner length, width, and water height to litres, US gallons, and UK gallons. Substrate litres use the footprint times gravel depth. Glass thickness is not subtracted; measure inside.
A bowfront adds an elliptical cap: extra ≈ (π × length × bulge × height) / 4 on top of the rectangular box. A 90 × 45 × 45 cm box with a 10 cm bulge is about 214 L before substrate.
Water volume
214.1 L
Results can be wrong. This calculator is unofficial. Figures can be incomplete, rounded, or not updated. Use them at your own risk and check a tape, datasheet, ball band, or official chart before cutting, mixing, buying, or publishing. Measure inside the glass. Hexagon length is point-to-point; a flat-to-flat measure will mis-size the tank. Bowfront extra is an ellipse, not the real curve. Limits of liability are in the terms of service.
Inner. Outer millimetres include glass thickness and overstate water.
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Publisher notes · reviewed 29 October 2026
Extra ≈ π × length × bulge × height / 4 on top of the rectangular box. Measure the centre bulge, not the glass thickness.
Retail “55 gallon bowfront” labels can include the hood. This page is water volume from inner measures.
90×45×45 cm + 10 cm bulge
About 214 L before substrate.
