groundmath

Lawn area calculator

Split your lawn into simple shapes, measure each in feet, and get the total in square feet, square yards, and acres. Then hand the same measurement straight to the sod, topsoil, or gravel calculator — measure once, use it everywhere on this site.

✓ Formula v1.0 · exact unit definitions only — no measured material data
Sections of your lawn — measured in feet
Your total area

Add at least one section above to see your lawn's square footage.

How this is calculated

  1. Each shape's area is computed and summed:rectangle = length × width, circle = π × (diameter ÷ 2)²,triangle = base × height ÷ 2.
  2. Conversions are exact definitions, not measurements: 1 square yard = 9 square feet, 1 acre = 43,560 square feet, and 1 foot = 0.3048 m exactly, per theNIST Guide to the SI (SP 811), Appendix B: Conversion Factors (accessed2026-07-31).

How to measure your lawn

Work section by section: break the lawn into rectangles, circles, and triangles, measure each in feet with a tape measure or measuring wheel, and let the calculator add them up. That is the methodPurdue Extension (AY-28-W) (accessed2026-07-31) recommends — divide the lawn into several squares, rectangles, or circles, calculate each area, and sum them. For a whole property it is often faster to measure the full lot and subtract the footprint of the house, driveway, patio, and planting beds — enter the lot as one rectangle, measure the subtractions, and take the difference before entering it, since the entries above only add.

Measure once, use it everywhere

Your shapes are saved into this page's web address as you type, so the “use this measurement in” links under the result carry your exact lawn — every shape, not just the total — into any other calculator on this site. Deciding between seeding over new topsoil and laying sod? Open both calculators from the same measurement and compare real order quantities. The link is also shareable: bookmark it, or send it to whoever is getting the quotes.

Frequently asked

How many square feet is an acre?
Exactly 43,560 square feet — the historical surveyor's chain-by-furlong rectangle, 66 ft × 660 ft. A quarter-acre lot is 10,890 sq ft; a typical lawn is a fraction of that once the house, driveway, and beds are subtracted.
How do I measure an irregular lawn?
Split it into simple shapes — rectangles, circles, triangles — measure each in feet, and add them as separate entries above; the totals are additive. That is the method university extension services teach. For a curved bed edge, a circle or triangle approximation is well within the accuracy a material order needs.
How accurately do I need to measure?
To the nearest foot is enough. Bulk material is ordered in half-yard or full-yard increments and sod in whole rolls or pallets, so inch-level precision disappears in the rounding — and the material calculators this page links to show their waste and rounding assumptions separately, so you can see exactly how much slack your order already carries.
How many square feet are in a square yard?
Exactly 9 — a square yard is 3 feet by 3 feet. Divide your square footage by 9 for square yards, the unit sod vendors usually quote.

Quantities on this page are planning estimates, not engineering advice or a purchase guarantee — product sizes vary by producer, so confirm coverage with your supplier before ordering.