🌱 Lawn Square Footage Calculator
Calculate your lawn area in seconds
Your Lawn Size Is
💡 Quick Tips
- Measure at the longest and widest points
- For irregular shapes, break into sections
- Add 5-10% extra for trimming waste
- Round measurements to nearest foot
Seed, fertiliser and weed treatment are all sold by area, so your lawn’s square footage is the number every other lawn calculation starts from. Enter the measurements above and the calculator returns the area — including for circles and triangles, which is where most lawns stop being simple.
How to measure a lawn that is not a rectangle
Almost no lawn is a neat rectangle, and this is where a general-purpose area calculator stops being useful. The practical method is to break the shape into pieces you can measure — a rectangle for the main area, a triangle for the corner it tapers into, a half-circle for the curved end by the border — run each through the calculator, and add the results.
- Measure to where the grass actually stops, not to the fence line behind it.
- Subtract what is inside the lawn but is not lawn — a shed base, a pond, a path across the middle, an island bed. This is the step people skip, and it is why so many bags of fertiliser get over-applied.
- No tape measure? Pace it. A normal adult stride is close enough to three feet for this purpose.
- For an awkward curve, measure the widest point across and treat it as a square of that size. You will over-estimate slightly, which is the right direction to be wrong in.
Turning square feet into bags
Most lawn products state coverage per 1,000 square feet. Divide your figure by 1,000 and multiply by the rate on the bag. The table below gives the usual starting points, but the bag always wins if it disagrees.
| Job | Typical rate per 1,000 sq ft | For a 5,000 sq ft lawn |
|---|---|---|
| Overseeding an existing lawn | 3 – 5 lb seed | 15 – 25 lb |
| New lawn from bare soil | 6 – 10 lb seed | 30 – 50 lb |
| Granular fertiliser | 1 lb nitrogen | check the analysis on the bag |
| Lime | 50 lb (per soil test) | 250 lb |
| Topdressing, quarter inch | 0.75 cu yd | 3.75 cu yd |
Seed rates differ sharply between overseeding and starting from scratch — usually about half as much for the former — so check which figure the bag is quoting before you buy. If you are seeding, which grass seed establishes fastest is worth reading first, and overseeding without aerating covers the method for thickening a lawn you already have.
Buy about 5% more than the number says
Spreaders are never perfectly calibrated and nobody walks a perfectly even path. Running out with one strip left to do means an obvious green stripe across the lawn for the rest of the season. A little left in the bag costs far less than an uneven finish.
What else the number is good for
Once you know the area, several other jobs stop being guesswork: how much sod to order if you are laying turf, how long watering takes to deliver an inch, and roughly what a contractor should quote. Our roundup of the best lawn fertilizers lists application rates alongside each product, so the square footage translates straight into a shopping list.