How do you figure Sq. ft. on an odd shaped yard???


LawnSite Member
I asked this question on the Landscape board but I wanted to get your input.

From time to time I have to try and figure the sq. ft. of an odd size yard. Up to now I have been figuring length times width and then subtracting some. So far this "eyeball method" has worked but I would like to be able to figure it exactly.

Do you guys use any specific formula for figuring sq. ft. on an odd shaped yard???

For instance how would you figure the sq. footage on a kidney bean shaped yard???

Thanks for the input!!!


LawnSite Senior Member
North Alabama
when figuring sq. footage for seeding I ran into the same problem. To solve the problem, I divided everything into general geometric shapes ( rec., circle, trinagles) Once the lawn was broken down to specific areas I measured them and did the calculations at home. If the lawn was not symetrical to rec., circle ,or triangle I rounded off the nearest foot and eye balled some measurements. I believe square footage of a lawn is not an exact science. If I can get +/- 50 sq.ft. I'm happy with my measurements on irregular shaped lawns. (Always error on the high side so you personally don't take a loss.) If the estimated sq. footage is for mowing +/- 50 sq.ft shouldn't matter that much.

P.S. to determine the measurements I use a 12" diameter wheel and it seems to be very efficient.

ok man I looked through and swear I saw the formula I usu just est a little above for irreg shapes..its better explkained w pic but do a diagonal-longest line thhen mult by avg of sides like you have an oval 100 nft long meas width at every 10 feet divide by 10 mult by diagonal...this measurement however would give you the same as a ractangle so curves take a bit longer but this is the matehmatically correct way to do it

[Edited by Lawngeek on 01-25-2001 at 08:44 PM]


LawnSite Member
South is right on the nose.
Just take it and make it into several common shapes,then add all the Sq. ft together


LawnSite Senior Member
The method that Ssouth is a acceptable way to measure irregular shape bounderies. I have a more accurate way from one of my pesticide training books, but NO way I could describe it without a picture. If no one else posts the same method in a few days, I will fire up my scanner, and get instructions from Eric on how to post a picture of the formula and accompaning picture to figure out the formula.

nono my man you've got to see it pictorally take a loaf of bread measure how long-12 now take and do 10 vertical slices measure them divide by 10 you have an average multiply this by diag length - sq footage I have a beatiful pic in my textn