How to Measure Your Lawn


One of the most crucial steps any homeowner or professional can take is to properly manage their lawn is to measure its area. The proper application of fertilizer, lime and pesticides is based on knowing how much is needed per unit of area. Errors in rate or uniformity may waste money, injure plants, damage the environment, and fail to control pests. Smaller sites are usually measured in square feet. Larger areas are measured in acres. One way to measure your lawn is to match each part of irregular site to the closest geometric shape, then find the area of each part and add them up to get the total area to be treated. Make adjustments if a driveway, mulch bed, dog pen or building takes up space in the treatment area by determining the area that these sites occupy and subtract it from the total area.

Geometric shapes

Geometric shapes are common is home lawns. Some irregular shapes can be divided into smaller geometric shapes, and their areas added together to estimate the area of the entire lawn.


Irregular Shapes

Many landscape designers want to create a lawn that gives a more natural and pleasing appearance, in some ways, irregularly shaped areas are easier to measure than geometric shapes. There are two different methods for determining of irregular shapes. The offset method is most often used to measure lawns of irregular shapes. Another is average radius method.

Offset Method

The offset Method simply divides irregular shapes into smaller rectangles or trapezoids to estimate the area.

Step 1: Determine the longest line and label the ends A and B.
Step 2: Choose how many offset lines to create so that the offset lines divide line A-B into equal parts. Tip from the pros: The closer the offset lines are to one another, the more accurate the sq footage will be.
Step 3: Measure the length of each offset line. These are measured from the edge of the area to the other.
Step 4: Add up all the lengths of offset lines and multiply this total by the distance between offset lines.


The Modified Offset Method

Areas such as ponds, lakes and rivers cannot be calculated by the offset method so in place is the modified offset method.


Step 1: Make a rectangle around the area to be measured. Label the corners A, B, C, D and measure the length and width.

Length (A to B; C to D) = 60 ft
Width (A to C; B to D) = 40 ft

Step 2: Mark pairs of offset lines (10ft) along each length line to the nearest perimeter of the object.

Step 3: Measure the length of the pairs of offset lines by measuring from the outside edge to the edge of the pond.

E1=12ft F1=8ft G1= 10ft H1=8ft I1=16ft
E2=10ft F2=18ft G2= 14ft H2=6ft I2=16ft
=22ft = 26ft =24ft =14ft =32ft

Step 4: Subtract the value of each pair of offset lines from the width (40ft) and then total.
E 40-22=18
F 40-26=14
G 40-24=16
H 40-14=26
I 40-32=8
Total =82ft

Step 5: Multiply the total by the distance between the offset lines.
(82ft)(10ft)=820 sq ft