## How can I find out the size of my pond? | Pond & Lake Q&A

How can I find out the size of my pond?
Paul – Scottsdale, AZ

While most of us could take a quick guess at the size of our pond many times we don’t really know the true dimensions. Most products for pond treatment such as aquatic herbicides, aquatic algaecides, and pond dye are dosed based on surface acres or square footage. Being off by 30 ft. in pond measurement could mean reducing or increasing your pond size enough to make a treatment ineffective. So how should you go about getting the correct measurements of your pond?

It is important to understand that measuring your pond involves using a universal unit of measure like feet and inches. While you may know what you mean when you say the water comes up to your chin that will be interpreted differently from person to person. For measuring depth, tie a weight to some string and let it sink to the bottom of the pond, pull the string in just enough so there is no slack left. Mark the string at the surface of the water. Once you bring up your weight lay the line out on the ground and measure it with a tape measure for a more accurate reading. Take measurements in multiple areas as most ponds are not the same depth throughout. When measuring overall lengths and widths you can use a flexible tape to gather dimensions or measure your stride and pace off the dimensions. Typically one pace is around 3ft. If your pond is irregular in shape you can also use online applications like Google Earth and Bing to locate your pond and measure it from the comfort of your computer chair.

To calculate your pond size you must first figure the square footage of the pond. Multiply the length of your pond by the width to find your square footage. Let’s use a 200’ long by 100’ wide pond as an example. 200’x 100’ equals 20,000 square feet. 1 surface acre consists of 43,560 square feet. To find out how our 20,000 square foot pond measures up to 1 acre we can simply divide 20,000 by 43,560. You should end up with .45 surface acres or slightly under ½ surface acre. If your pond better represents a triangle or circle you can use the equations given below to help calculate the total surface area.

If you are unsure of the best method for measuring your pond or want a second opinion you can always contact one of our pond guys and gals toll free at 866.766.3435 or use our web calculator.

Pond Talk: Was your pond dimension “guess” accurate with your actual pond measurements?

### 5 Responses

1. Yes but if you tie a knot at every foot, the string is going to get shorter with each knot, thus ending with an incorrect measurement.

• Hi Cindy,

Thank you for your comment. The small knot that you would tie would not make much of an effect on the length of string, as long as there was a foot inbetween each one your measurement should come out correct.

• Hi Cindy,
I am sure that kathiethueme would measure the string AFTER the knots are tied. Just an observation

2. I use a string with a weight on the end and then come up the string and tie a knot in the string at one foot intervals. I can then cover my pond in a boat and drop the weight overboard and as I pull the string up thru the other hand count the knots to get an estimate of the various depth locations.
This is less time consuming than taking a measure of the string after each depth check. This works very well on the larger ponds.where one is taking a number of depth readings in order to get a better average depth.