How to measure for topsoil
Break a complicated garden into simple, non-overlapping areas. Measure each area at ground level and use the depth of soil you will actually add.
1. Sketch the site
Mark beds, lawn sections and curved areas separately. Do not count paths, patios or areas that will not receive soil.
2. Choose simple shapes
Use rectangles for straight runs, circles for round beds and triangles for tapered corners. For irregular outlines, divide the site into several shapes rather than guessing one bounding rectangle.
3. Measure depth separately
Depth is not the height of an edging board unless the whole space will be filled to that height. Record the actual layer being added in each section.
4. Check your total
The calculator shows each area’s base volume. Compare those subtotals with your sketch before adding an extra-material allowance.