HowManyFish.com Aquarium Estimator Tools

How Big is My Aquarium?

Calculate volume and weight of filled aquarium

How much water does your aquarium hold? How much will your aquarium weigh when it is full?

Use our Aquarium Volume and Weight Calculator (available in U.S. and metric units) to find out how much your complete tank will hold and weigh. Can your floor support a heavy aquarium?

Quick Aquarium Weight Calculation (U.S. units)

Scroll down for metric unit calculation

Enter U.S. gallons to get quick aquarium weight estimate

Gallons your tank holds:

Your tank weighs approximately lbs. when full.

The Quick Calculation does not account for substrate, decorations, the weight of the empty aquarium, stand, etc. For a more precise estimate, use the Detailed Calculation.

Detailed Aquarium Weight Calculation (U.S. Units)

Please enter U.S. units to approximate
the weight and volume of your filled aquarium

Length inches (required)

Width inches (required)

Depth of Water inches (required)

Optional: Depth of Substrate inches
[enter "0" (zero) if unknown]

Optional: Weight of Empty Aquarium (and other elements, such as decorations or stands, if desired) lbs.
[enter "0" (zero) if unknown]

Your aquarium weighs about lbs.

Your aquarium would hold about gallons with no substrate or decorations.

No result? Make sure you entered numbers into all fields. Calculator will not work if any fields are blank or contain letters.

Aquarium Volume and Weight Calculator (Metric Units)

If completely full, the weight of the water alone in your aquarium in kilograms (kg) is equal to the number of litres (L) it contains. However, this does not account for the weight of the substrate, decorations, the empty tank, or how full the tank is filled. Use the following aquarium weight calculator to more closely approximate the total weight of your aquarium.

Please enter metric units to approximate the weight and volume of your filled aquarium

Length cm (required)

Width cm (required)

Depth of Water cm (required)

Optional: Depth of Substrate cm (enter "0" if unknown)

Optional: Weight of Empty Aquarium (and other elements, such as decorations or stands, if desired) kg (enter "0" if unknown)

Your aquarium weighs about kilograms (kg)

Your aquarium would hold about litres (L) with no substrate or decorations.

No result? Make sure you entered a number in all fields. Calculator will not work if any fields are blank or contain letters.

What the Aquarium Weight Results Mean

These results are an approximation. Actual volume and weight may vary, depending on how full the tank, type of substrate, filter, decorations, etc.

For the weight of the substrate, we are using the general approximation that wet gravel or sand substrate weighs about twice as much as the equivalent volume of water. This is based on U.S. and U.K. standardized weight-to-volume ratios of common materials.

For more information on fish stocking for beginners, see The Complete Aquarium by Peter W. Scott.