Corner Bow Front vs Corner Cylinder Aquarium Volume

Quick Answer

A corner bow front aquarium has two flat wall panels that meet at a 90-degree rear corner, with a gently bowed front between their front ends. A corner cylinder aquarium has a true quarter-circle curved front. They need different formulas and different calculators.

Shape Differences

Both shapes sit in a 90-degree room corner with two flat panels against the walls. A corner bow front has a gently curved front between the front ends of those panels, and the calculator models it as the triangle between the two wall panels plus a half-ellipse bow. A corner cylinder has a single quarter-circle panel centred on the room corner, sweeping from the end of one wall panel to the end of the other.

Measurement Differences

A corner bow front requires three measurements: front span, bow depth, and height. A corner cylinder requires only two: radius and height. The corner bow front needs more measurements because its shape cannot be defined by a single radius. For tips on measuring your tank accurately, see our full measurement guide.

Formula Differences

The corner bow front uses V = (F² ÷ 4 + π × F × B ÷ 4) × H, where F is the front span and B is the bow depth. The corner cylinder uses the quarter-cylinder formula: V = (π × r² × H) ÷ 4. For a front that is exactly a quarter circle the corner cylinder formula is exact, and the corner bow front formula, which models the bow as a half-ellipse, reads about 5% higher.

Which Calculator Should You Use?

Look at your tank from above. If the front glass bows gently outward between the front ends of the two wall panels, use the corner bow front calculator. If it is a smooth quarter-circle curve sweeping directly from one back wall to the other, which is the case when the distance from the rear corner to the middle of the front glass equals the length of a wall panel, use the corner cylinder calculator.

Example Comparison

Take a corner tank whose front corners are 20 inches apart and whose water is 24 inches deep, so each wall panel is about 14.14 inches long. As a corner cylinder with that radius (r² = 200): V = (π × 200 × 24) ÷ 4 = 3,770 cubic inches = 16.3 gallons. As a corner bow front with a 3-inch bow depth: V = (20 × 20 ÷ 4 + π × 20 × 3 ÷ 4) × 24 = (100 + 47.12) × 24 = 3,531 cubic inches = 15.3 gallons. Each extra inch of bow depth adds π × 20 × 24 ÷ 4 = 377 cubic inches, about 1.6 gallons. Use the unit converter to translate these gallon values to litres.

Try the Calculators

Corner Bow Front Aquarium Volume Calculator Corner Cylinder Aquarium Volume Calculator

Frequently Asked Questions

Which corner tank shape holds more water?

It depends on the bow depth. With the same two front corners, a corner cylinder has a fixed quarter-circle front, while a corner bow front holds more as its bow gets deeper. For front corners 20 inches apart and 24 inches of water, a corner bow front with a 3-inch bow depth holds about 15.3 gallons and the corner cylinder about 16.3 gallons.

Can I use one calculator for both shapes?

No. The formulas and measurements are different: a corner cylinder needs only its radius, while a corner bow front needs its front span and bow depth. Using the corner cylinder calculator for a corner bow front, or the reverse, gives a wrong volume. The one overlap is a corner bow front whose front is exactly a quarter circle: the corner cylinder calculator is exact for it, and the corner bow front calculator reads about 5% higher.

Which corner shape is better for reef tanks?

Both work well for reef tanks in corner placements. Corner cylinders offer a wider, more panoramic curved viewing angle. Corner bow fronts provide a more subtle curve.

How do I measure the bow depth on a corner bow front?

Lay a straight edge across the two front corners, where the curved glass begins. Measure from the straight edge to the curved glass at the deepest point of the bow, at a right angle to the edge. Alternatively, measure from the rear corner to the middle of the front glass and subtract half the front span.

Are corner bow front tanks more expensive than corner cylinder tanks?

Both are specialty shapes that cost more than standard rectangular tanks. Corner bow fronts tend to be slightly more expensive because they combine multiple curved and flat panels.