Aquarium Calculator
Calculate aquarium volume and capacity for different tank shapes and sizes
Calculate Aquarium Volume
Aquarium Volume Results
Example Calculations
Standard 75-Gallon Rectangular Tank
Dimensions: 48" × 18" × 21" (122cm × 46cm × 53cm)
Volume: 122 × 46 × 53 = 297,292 cm³ = 297.3L = 78.5 gallons
Fish Capacity: ~297 small fish or 29-39 medium fish
Cylindrical Tank (20" diameter × 24" height)
Calculation: π × (25.4cm)² × 61cm = 123,370 cm³
Volume: 123.4L = 32.6 gallons
Fish Capacity: ~123 small fish
Bow Front Tank (36" × 15" × 20", Full Width 18")
Base Volume: 91.4 × 38.1 × 50.8 = 176,949 cm³
Bow Addition: ~15,000 cm³ (curved section)
Total Volume: ~192L = 50.7 gallons
Aquarium Shapes
Rectangular
Most common tank shape
L × W × H
Cube
Equal sides all around
L³
Cylinder
Round tank
π × r² × H
Bow Front
Curved front panel
Rectangle + curve
Fish Stocking Guidelines
1 liter per 1 cm of fish (general rule)
Smaller tanks need better filtration per fish
Consider fish behavior and compatibility
Account for decorations and equipment
Leave 10-15% space for maintenance
Understanding Aquarium Volume Calculations
Volume Formulas by Shape
Rectangular Tank:
Volume = Length × Width × Height
Cylindrical Tank:
Volume = π × (Diameter/2)² × Height
Bow Front Tank:
Volume = Rectangle + Curved Section
Why Calculate Volume?
- •Determine proper fish stocking levels
- •Calculate water treatment dosages
- •Size filtration and heating equipment
- •Plan water changes and maintenance
Unit Conversions
Volume:
1 Liter = 1,000 cm³
1 US Gallon = 3.785 Liters
1 Imperial Gallon = 4.546 Liters
Length:
1 inch = 2.54 cm
1 foot = 30.48 cm
Important: These calculations give theoretical volume. Actual water capacity will be less due to substrate, decorations, equipment, and the fact that tanks are never filled to the absolute top.
Tank Shape Comparison
| Shape | Pros | Cons | Best For |
|---|---|---|---|
| Rectangular | Maximum swimming space, easy to clean | Basic appearance | Most fish species |
| Bow Front | Elegant curved view, less distortion | More expensive, harder to clean corners | Display tanks, living rooms |
| Cylinder | 360° viewing, unique appearance | Limited swimming patterns, hard to aquascape | Small spaces, single species |