University of Connecticut Cooperative Extension System: Water Quality and the Home Landscape

Sustainable Landscaping: Turf

by Karl Guillard

Figure square footage

The amount of fertilizer applied is based on the amount of lawn area in square feet. To determine the size of your lawn, divide the lawn area into a series of rectangles, triangles, and circles, figure the square footage of each and total them up.

  • For areas that are roughly square in shape, multiply the length times the width to get the total square footage of the area (l x w = area)
  • For areas that are roughly triangular in shape, take one half the length of the base and multiply by the heighth to get the square footage (1/2b x h = area)
  • For areas that are roughly circular in shape, multiply pi (3.14) by the square of the circle's radius to get the square footage (ii x r2 = area)

Since bags of lawn fertilizer are labeled according to how much square footage they are formulated to cover, choose the bag size closest to the actual square footage of the lawn.