Lay out the course that your edging will follow by placing a garden hose along this path.
Measure the length of the path where the garden hose was placed to determine how much space the edging will cover. Write this number on a piece of paper and label it "A."
Contact your landscape supply store to determine the average length of the flagstone that you will use. Write this figure on paper and label it "B."
Divide "B" into "A" to receive the total of field stones you will use. Round partial numbers up to the nearest whole number. This total is "C."
Figure an extra percentage of stones to purchase for waste. In all building projects, waste refers to the materials (stone, tile or even carpet) that you have to cut down to fit the dimensions of your building project. To calculate waste quantities, divide "C" by 10. Add one-half of this total (5 percent) back to "C" for the number of field stones you should purchase.