How to Calculate Area of An Irregular Plot or Land

If you are having a cross plot/land (the dimensions of plot is not equal in any side) and you want to calculate the area, Here we are going to share an easy formula to calculate the area of an irregular plot or land with an example.

To easily understand the method lets take an irregular land example as shown below

Lets calculate the area of the above shown land with this formula

Area = √s(s-a)(s-b)(s-c)

Where S= a+b+c/2

Now to calculate the area of this irregular land we need to divide the land into two triangle as shown below.

Lets calculate the value of “S” for each triangle to substitute in formula

Triangle ACD, S= b+d+e/2  

before substituting the values convert all inches into feet by dividing with 12

S = 68.045’+42’+41’/2  = 75.522′

Now we have the value of S, substitute it into the formula for triangle ACD

Area of triangle ACD = √s(s-b)(s-d)(s-e)

Area of triangle ACD = √75.522(75.522 – 68.045) (75.522 – 42) (75.522 – 41)

Area of Triangle ACD = 808.37 sft

2. Triangle ABC, S= a+b+c/2

S = 39.5’+68.045’+60.99/2 = 84.267′

Area of triangle ABC = √s(s-a)(s-b)(s-c)

Area of triangle ABC = √84.267(84.267 – 39.5) (84.267 – 68.045) (84.267 – 60.99)

Area of triangle ABC = 1193.50 sft

Now add both the areas i.e, area of triangle ACD and area of triangle ABC

Total Area of land = Area of triangle ACD+ Area of triangle ABC

Total Area of land = 808.37+1193.50

Total Area of land = 2001 SFT

If you want to covert the area into SqYDS then just divide the area by 9

2001/9 = 222.33 SqYDS

Or if you know how to operate AutoCAD you can simply draw the land with the same dimensions you got on field and Enter the command “AA” and specify all corners of the land and press enter you will get the exact area of land.

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