US Aquarium Volume & Equipment Calculator
Accurately calculate your tank capacity in US Gallons, estimate net water volume, and get industry-standard equipment recommendations.
Calculated Tank Capacity
Recommended Equipment Specs:
- Filter Flow Rate: 0 GPH (4x – 6x turnover rate)
- Heater Wattage: 0 Watts (3W – 5W per gallon)
- Substrate Weight Needed: ~0 lbs (10 – 12 lbs per gallon of substrate volume)
Understanding Aquarium Volume Calculations
When setting up a freshwater planted tank or a marine reef system in North America, knowing the precise water volume is essential. Aquarium dimensions provided by manufacturers usually indicate the gross volume based on outer glass measurements. However, biological filtration capacity, chemical dosing, and medication treatments depend entirely on the net water volume.
The Standard US Gallon Formula
To find the total cubic volume of a rectangular glass tank in inches, apply the standard imperial conversion formula where one US gallon equals 231 cubic inches:
Gross Gallons = (Length × Width × Height) ÷ 231
To calculate the net water volume accurately, our calculator automatically subtracts a 1-inch top clearance gap (empty space at the water surface) and the volume displacement taken up by your chosen substrate depth.
Standard US Aquarium Dimensions Reference Chart
The table below outlines common standard glass tank sizes in the US market, along with their respective gross capacities and standard filtration flow requirements:
| Tank Designation | Dimensions (L × W × H in inches) | Gross Capacity (US Gal) | Filter Flow (4x – 6x GPH) |
|---|---|---|---|
| 10 Gallon Standard | 20″ × 10″ × 12″ | 10.4 Gal | 40 – 60 GPH |
| 20 Gallon Long | 30″ × 12″ × 12″ | 18.7 Gal | 80 – 120 GPH |
| 29 Gallon Standard | 30″ × 12″ × 18″ | 28.1 Gal | 110 – 170 GPH |
| 40 Gallon Breeder | 36″ × 18″ × 16″ | 44.9 Gal | 180 – 270 GPH |
| 55 Gallon Standard | 48″ × 13″ × 21″ | 56.7 Gal | 230 – 340 GPH |
| 75 Gallon Standard | 48″ × 18″ × 21″ | 78.5 Gal | 310 – 470 GPH |