Lawn Area Calculator
Enter the lot size and subtract what isn’t grass to find your lawn area.
Lot size
Subtract areas that are not lawn (square feet)
Coverage settings
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Try YardDraftHow to measure your lawn
The easiest method is to measure the whole lot, then subtract everything that isn’t grass. Measure the lot length and width in feet (a measuring wheel, a tape, or the area tool on a satellite map all work), then subtract the house footprint, driveway, walkways, patio, and garden beds. What’s left is your lawn area in square feet.
Why lawn area matters
Almost everything you buy for a lawn is priced or dosed by area: fertilizer, weed control, grass seed, sod, and lawn care services. Fertilizer bags list the square footage they cover, so the bag count above tells you how many to buy. Sod comes in rolls of about 10 square feet or in large rolls and pallets, so check the size listed in the store.
Square feet and acres
One acre is 43,560 square feet. A quarter acre lot is 10,890 square feet, but the lawn on a quarter acre is usually much smaller once the house and driveway are removed.
Measuring odd shapes
Split the yard into rectangles, triangles and circles. Rectangle area is length times width. Triangle area is half of base times height. Circle area is 3.14 times radius squared. Add the pieces together and type the total into the lot size box.
Worked example
A lot measures 80 ft by 120 ft, which is 9,600 square feet. Subtract the house (1,800), driveway (600), patio and walks (400), and garden beds (500). That leaves 6,300 square feet of lawn. If a fertilizer bag covers 5,000 square feet, you need 6,300 ÷ 5,000 = 1.26 bags, so buy 2 or save the leftover for next time. For sod in 10-square-foot rolls you would need about 630 rolls, plus 5 to 10% extra for cuts and waste.
Acres to square feet
| Lot size | Square feet |
|---|---|
| ⅛ acre | 5,445 |
| ¼ acre | 10,890 |
| ½ acre | 21,780 |
| 1 acre | 43,560 |
Reading a fertilizer or seed label
The coverage number on the bag is the area it treats when spread at the labeled rate. Spreading more thickly to use it up does not help, and too much fertilizer can burn the grass. Seed labels give a separate rate for a new lawn and for overseeding, so match the rate to the job. Many spreaders have a setting chart on the bag for each brand.
Tips for accurate measurements
- Measure beds and the house footprint from a satellite map to save walking the yard with a tape.
- Round the numbers you subtract down slightly. Overestimating the lawn by a little is safer than running short mid-job.
- Re-measure if you add a patio, shed or garden bed. The lawn shrinks every time.
Frequently asked questions
Should I measure the lot or the lawn?
The lawn. Lot size includes the house, driveway and beds, none of which need seed or fertilizer.
How do I measure a curved lawn?
Break it into rectangles, triangles and circles, work out each area, and add them up. An approximate answer within 5 to 10% is fine for buying supplies.
How do I use this to price mowing?
Take the lawn area from this calculator and enter it in the lawn mowing price calculator to get a per-visit price.