How to Measure Your Lawn

Why your square footage matters

Fertilizer, grass seed, pre-emergent, and weed control are all labeled per 1,000 square feet. If you guess your lawn size, you guess your dose, and that is how lawns end up burned, striped, or underfed. Measure once, write it down, and you will reuse that number for years.

The manual way

1. Break your lawn into simple shapes. Most yards are not one neat rectangle. Picture the grass as a set of rectangles, triangles, and the occasional circle, and handle each piece on its own.
2. Measure each piece. Use a tape measure or a measuring wheel for accuracy. No tools handy? Pace it out: an average adult step is close to 2.5 feet, so count your steps and multiply.
3. Do the area math. A rectangle is length times width. A right triangle is base times height, divided by 2. A circle is 3.14 times the radius times the radius (the radius is half the width).
4. Subtract what is not grass. Take out the house footprint, driveway, patio, deck, and planting beds. You only want the green stuff.
5. Add the pieces together. Sum every shape. That total is your lawn's square footage.

Worked example: a back lawn that is a 60 by 40 ft rectangle (2,400 sq ft) plus a triangular side strip with a 30 ft base and 20 ft height (30 x 20 / 2 = 300 sq ft) comes to 2,700 sq ft. Subtract a 10 by 12 ft shed (120 sq ft) and you have about 2,580 sq ft of lawn.

The easy way with SimpleLawn

Dragging a tape measure around the yard gets old fast, especially for an odd-shaped lot. In SimpleLawn you open the satellite map, tap around the edge of each area, and it calculates the square footage of every zone and adds up the total for you. No shapes, no formulas, no pacing the yard.

Once your lawn is measured, every other number gets easy. Next up: how much fertilizer you actually need.