How to measure an irregular garden
Almost no garden is a neat rectangle. The trick is not clever geometry — it is splitting the space into simple shapes, measuring each one, and adding them up.
Step 1 — sketch it
Draw the outline on paper, roughly to scale. Then draw straight lines across it to divide it into rectangles, right-angled triangles and circles. Number each piece.
Step 2 — measure each piece
Rectangle: length × width. Right-angled triangle: base × height ÷ 2. Circle: 3.14 × radius × radius, where the radius is half the diameter. For a curved edge, average the widest and narrowest points and treat it as a rectangle — the error is smaller than the waste allowance.
Step 3 — add them up
Total the areas and you have the figure every calculator on this site needs. Our area builder does this part for you: add a section per shape and it keeps a running total, with a labelled diagram of each piece.
Practical tips
Use a 30m open-reel tape, not a 5m pocket tape. Measure at ground level, keep the tape taut, and take every measurement twice. Add 5–10% waste on top of the final figure for cuts and settling — always round up to the next bag.