📐 Lawn Area Calculator

Four shapes, four formulas

Pick the shape and the tool applies the matching geometry, in feet:

rectangle  A = length × width
circle     A = π × radius²
triangle   A = 0.5 × base × height
L-shape    A = (l1 × w1) + (l2 × w2)

The defaults give 1,500 sq ft for the 50 × 30 ft rectangle, 1,257 for a 20 ft radius circle, 400 for a 40 ft base by 20 ft triangle, and 1,800 for the L-shape, which is 1,500 plus a 20 × 15 ft wing. Totals are rounded to whole square feet.

Measuring the lawn, not the lot

• Leave out the hardscape. House, drive, patio, beds and the pool are not turf. Measure them and subtract, or measure the grass in pieces to begin with.
• Split anything awkward. Run the tool once per section and add the totals; the L-shape option just saves you doing that twice.
• Triangles close the gaps. A wedge of grass between a curving path and a fence is close enough to half its base times its height.
• No tape? Pace it. Walk the edge counting steps, then check your stride against a tape once - most adults land near 2.5 ft.

Frequently asked questions