The irregular spaces might be thought to be hard to compute but then it becomes easy when the irregular space is broken into smaller parts. Whenever possible, break the shape into a rectangle, square or circle. Measure the parts individually and take the volume of each part. When finished, add the totals of the entire estimate. Most of the builders calculate the concrete yardage in this manner since this makes it easier to calculate the complex layouts into an accurate calculation. Accuracy is important because irregular shapes may lead to more mistakes in case they are estimated roughly. Graph or digital tools could be beneficial. This is effective in custom patios, walkways that are curved or landscape projects in which the standard rectangular calculations are not applicable.