# How do I measure the surface acres of my pond?

## How do I measure the surface acres of my pond?

/ January 17, 2019

Measuring the surface acreage of your pond is going to differ depending on the shape.  Use the following formulas to help you.

Rectangular or Square Pond – Length x Width / 43,560
Example: for a pond that is 100 feet long by 50 feet wide – 100 x 50 = 5000 sq. ft. 5000/43,560=.115 surface acres
Circular pond – Circumference Squared / 547,390
Example: for a pond with a 300′ circumference (shoreline in feet around the entire pond) – 300 squared = 90,000; 90,000/547,390= 0.16 surface acres
Irregular Shaped Ponds – There are many methods to calculate irregularly shaped ponds.  A common method is using the formula to calculate the area of a trapezoid.
Example: a pond is 500 feet long but 200 feet wide at one end and 400 feet wide at the other. This shape can be calculated like a trapezoid using the average width to find the area
(Width 1 + Width 2)/2 * Length/43,560
(200+400)/2*500=75,000 sq. ft. 75,000/43560=1.72 surface acres
For ponds that are very irregular in shape you may need to divide into sections, or multiple trapezoids, then add the totals together
If you are still unsure, AQUA DOC can assist, in most cases, by mapping the pond.  Please feel free to contact us!