Pond Calculator

What Is a Pond Calculator?

A pond calculator helps you plan a backyard fish pond or garden pond by estimating pond volume, liner dimensions, and liner area. Enter your pond shape and dimensions to get gallon capacity and the liner size you need to purchase. For swimming pools, use our Pool Calculator.

How to Calculate Pond Volume

Pond volume equals surface area multiplied by average depth:

$$ V = A \times d $$

For a rectangular pond, area is length times width. For a round pond, area is $\pi r^2$. For an oval pond, area is $\pi \times L \times W / 4$. Results are shown in gallons, liters, and cubic meters.

How to Calculate Pond Liner Size

Pond liner dimensions must account for depth and overlap around the pond edges:

• Liner length = pond length + 2 × (depth + overlap)
• Liner width = pond width + 2 × (depth + overlap)
• Liner area = liner length × liner width

The underlayment material typically uses the same dimensions as the liner. A 1-foot overlap is common for securing the liner around the pond perimeter.