Aquarium Calculator - Calculate Fish Tank Volume

Updated May 13, 2020
Author: Mike - FishLore Admin
Social Media: FishLore on Social Media

It is important to know the your aquarium size so that you can figure out what fish you can keep in it.

Ideally, you have researched your fish first and then picked your tank size to meet their needs.

In your research you will come across articles written by people using a different measuring system than you (english or metric) and the converters on this page can quickly help you perform these conversions.

There are several calculators on this page and you can use the quick links below to jump to the one you need.

Quick Jump Menu:
Rectangular Tank Size
Cylinder Tank Size
Hexagon Tank Size
Fishless Cycle Ammonia Calculator
Heater Size Calculator
Chiller Size Calculator
Fahrenheit to Celsius
Gallons to Liters
Inches to Centimeters
UK Gallons to US Gallons
Meters to Feet
Convert Meq/L to dKH CaCO3 (ppm)

 

Rectangle Fish Tank Volume in Gallons

rectangular aquarium volume calculator
Aquarium volume is:

*Note: aquarium volume will most likely be less than the above calculated numbers due to water displacement from sand, gravel, driftwood, decorations, tank inhabitants, etc.

Next: Get Fish Stocking Suggestions for aquariums this size.
 

Cylinder Aquarium Volume

cylinder aquarium size calculator
Aquarium volume is:

*Note: aquarium volume will most likely be less than the above calculated numbers due to water displacement from sand, gravel, driftwood, decorations, tank inhabitants, etc.

For cylinder style aquarium stocking ideas: 3 Gallon Cylinder ideas?


 

Hexagon Aquarium Volume

hexagon aquarium size calculator
Aquarium volume is:

*Note: aquarium volume will most likely be less than the above calculated numbers due to water displacement from sand, gravel, driftwood, decorations, tank inhabitants, etc.

For hexagon stocking ideas: Fish that do well in a hexagon tank

 

Fishless Cycle Ammonia Calculator


new tanks would be at 0 ppm


4 or 5 ppm is good to start cycling

(convert liters to gallons)


ammonia strength % is on the bottle label

mL or drops of pure ammonia (1ml = 20 drops)
Be sure to check out the aquarium cycle article for more details and tips on fishless cycling!
Need help with fishless cycling? Post a thread in the aquarium nitrogen cycle forum.

 

Heater Size Calculator



A sample value here would be 5 or 10 degrees that you need to increase the tank temperature...

*Always unplug heaters before working on your aquarium! Please note that these heater size recommendations are approximations. Tank wall thickness and whether or not you use a lid or top on your aquarium could affect the heater size needed.


 

Chiller Size Calculator



BTU's:

*The formula used for calculating aquarium chiller size is: volume in gallons * 8.34 weight of 1 gallon of water * temperature pull down needed * 20% padding factor. It's better to use an oversized chiller (hence the 20% padding factor in the calculation) than an undersized one to ensure it lasts longer and doesn't have to work as hard and other factors that could impact the efficiency of the unit such as ambient room temperature.

 

Fahrenheit to Celsius


 

Celsius to Fahrenheit


 

Gallons to Liters


 

Liters to Gallons


 

Inches to Centimeters


 

Centimeters to Inches


 

UK Gallons to US Gallons


 

US Gallons to UK Gallons


 

Meters to Feet


 

Feet to Meters


 

Meq/L to dKH CaCO3 (ppm)

and

 

dKH to Meq/L and CaCO3 (ppm)


 

CaCO3 (ppm) to Meq/L and dKH

and

Site References :
Wikipedia - for some of the formulas used.

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