Aquarium Calculator - Calculate Fish Tank Volume

Updated March 22, 2019
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
Heater Size
Chiller Size
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 calculator
Aquarium volume is:

Next: Get Fish Stocking Suggestions for aquariums this size.

Cylinder Aquarium Volume

cylinder aquarium calculator
Aquarium volume is:

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

Hexagon Aquarium Volume

hexagon aquarium calculator
Aquarium volume is:

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

Heater Size



*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



BTU's:

*The formula used for calculating 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

Recent Forum Discussions:

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Next: Read about Saltwater Aquarium Supplements.

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

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