Whatever your lawn shape, if you can divide it up into the shapes pictured below (or very close to these shapes) this calculator will make estimating your total lawn area easy. Just enter the quantity and dimensions of each shape, and the calculator will do the rest.
When placing your order, keep in mind that it's generally not a bad idea to get a few spare rolls, just to be sure you don't run out while laying your turf.

Shape	Quantity	Dimensions in metres		Area m²
Rectangles	Quantity	Width	Height	Area
Right-angled triangles	Quantity	Width	Height	Area
Circles	Quantity	Diameter		Area
Semi-circles	Quantity	Radius		Area
			Total area m²