How to Measure Your Lawn Size in Square Metres or Feet

Quick answer Sketch your lawn and split it into simple shapes: rectangles (length times width), triangles (half base times height) and circles (3.14 times radius squared). Measure each with a tape, add the areas and subtract beds, patios and the driveway. Canadian bags often give rates in both square metres and square feet, so note the total in both.

Every bag of seed, fertilizer or lime gives a rate per area, and most spreader charts assume you know your lawn’s size. Most people guess. Ten minutes with a tape, or a traced map, takes the guessing out of every product you buy.

How do you measure a lawn by hand?

Split it into shapes you can calculate:

Shape	Formula	Example
Rectangle	Length × width	15 m × 10 m = 150 m²
Triangle	½ × base × height	½ × 8 m × 5 m = 20 m²
Circle	3.14 × radius²	3.14 × 2.5 m × 2.5 m = 19.6 m²

Front and back lawns are separate areas, and so is the boulevard strip if you look after it.

What about curves, beds and trees?

Draw a rectangle around a curved section and subtract the part that is not lawn. Subtract gardens, the patio, the driveway and mulched rings around trees. Round to the nearest 5 m² or 50 sq ft.

How much of each product do you then need?

Multiply the area by the rate on the bag. Many Canadian bags give both a metric rate and a coverage in square feet, so note your total in both units: multiply square metres by 10.76 to get square feet. The fertilizer calculation with NPK is in How Much Fertilizer for Your Lawn. For sod, add about 5 percent for cuts.

How does measuring on a satellite map work?

You trace the outline of the lawn on an aerial photo, point by point, and the app works out the area. It is quick for large or oddly shaped lots and easy to redo when you add a garden bed.

The example lawn in the app is a Toronto front lawn drawn as one area:

Mapped lawn area in the What a Green Lawn app for a lawn in Toronto — Toronto, September 20, 2026: the lawn drawn on the satellite map, 380 m² in one area.

In What a Green Lawn you tap the map to place corners and drag them to adjust. The area updates as you go, in square metres and square feet. Front and back lawns go in as separate zones, and the total drives the product amounts on the dashboard. Trees and shadows on the photo can hide the edge, so check one side with a tape.

How accurate does it need to be?

Within 5 to 10 percent is fine. Being far off is what hurts: a lawn guessed at 250 m² that is really 380 m² gets a third less fertilizer than planned, and one guessed too large gets too much, which is how burnt stripes happen. Measure once, write it down, and remeasure when the yard changes.

What a Green Lawn keeps the mapped area with your lawn and turns it into product amounts, so you measure once and skip the math at the spreader.

Step by step

Step 1 Sketch the lawn

Draw it on paper and split it into rectangles, triangles and circles. Mark beds and patios inside it.
Step 2 Measure each shape

Use a long tape or a measuring wheel and note each length and width.
Step 3 Calculate each area

Rectangle: length times width. Triangle: half the base times the height. Circle: 3.14 times the radius squared.
Step 4 Add, subtract and convert

Add the lawn shapes, subtract beds and patios, and convert if needed: 1 m² is 10.76 sq ft.

Frequently asked questions

How do I convert square metres to square feet?

Multiply square metres by 10.76. A 380 m² lawn is about 4,090 sq ft. To go the other way, divide square feet by 10.76.

How do I measure an irregular lawn?

Split it into rectangles and triangles that roughly fill the shape and add them up. Within 5 percent is plenty for buying products.

How much sod do I need?

Measure the area and add about 5 percent for cuts around curves, trees and edges. Sod is sold by the square foot or metre and by the pallet.

Can I measure my lawn from a satellite map?

Yes. Mapping sites and lawn apps let you trace the lawn on an aerial photo and calculate the area. Check against a tape measurement, since trees can hide the edge.