Formula
Net area is length times width.
Area to buy is the net area multiplied by one plus the waste percentage.
Rolls are that area divided by the area of one roll, rounded up.
Worked example
8 m by 5 m is 40.000 m². With 5% waste that is 42.000 m², 42.0 rolls before rounding, exact at 1 m² a roll.
Assumptions
Waste starts at 5%. The roll starts at 1 m² because many suppliers sell it that way.
The cut size of a roll is not fixed here. If your roll is a different area, change the field.
Checked
Checked 10 November 2026. Sherborne Turf sells rolls that cover 1 m² each. Change the roll area if the supplier you use cuts a different size.