Pond Volume Calculator: How Big Is My Pond?

You may be looking out at your yard and asking yourself, "How big is my pond?" When calculating the size of your pond, you first need to measure its area, then find the volume to determine how much water it can hold. The water volume of the pond will determine the amount of treatment product to use and how many fish can call it home.

How Much Water Is Needed for My Pond?

To find out how many gallons of water your pond needs, multiply its volume by 7.48, which is the number of gallons in a cubic foot. If you're using liters, multiply the volume by 1,000, the number of liters in a cubic meter.

How to Calculate Pond Volume

You need three measurements to calculate the volume of your pond: its length, width, and depth. 

Pond Volume = Length x Width x Depth

How to Measure Your Pond

For a pond that's rectangular or square in shape, you simply need to measure the length and width to find the square footage. From there, multiply the square footage by the pond's maximum depth to get the overall volume. 

For circular or irregularly shaped ponds, you need to use a slightly different formula. 

How to Measure a Circular Pond

To measure a circular pond, you'll need to find out the area of a circle. The formula for that is πr squared, or 3.14 times the circle's radius squared. 

Measure the pond's diameter, then divide that by two to get the radius. For example, if your pond has a diameter of 8 feet, the radius is 4 feet. The total area is 3.14 x (4 squared), or 50.24 feet.

Multiply that by the maximum depth to get the volume of the pond.

How to Measure an Irregularly Shaped Pond

If your pond has an irregular shape, such as a kidney bean or oval shape, the best way to measure is by creating straight lines around the perimeter of the pond, then measuring the length and width of those lines. 

Multiply the length and width to get an approximation of the pond's square footage. Then, multiply that by the maximum depth to get the volume of the pond.

Who to Hire to Create a Pond

Who should you hire to create a pond? Your best bet is to work with a local pond builder, who can help you determine the right size for your property, as well as the optimal shape for your needs. 

If you're hoping to stock the pond with aquatic life, such as koi or other types of fish, a professional pond builder can also provide guidance on the best species to choose and how many fish to stock in the pond.