What is the formula to figure concrete overrun?

To calculate concrete overrun, first determine the amount of concrete needed for the project by measuring the dimensions of the area to be filled and using the formula: Volume = Length × Width × Height. Then, consider factors such as waste, spillage, and variations in mix, typically adding 10-15% to the calculated volume for overrun. The formula can be expressed as: Total Concrete Needed = Volume + (Volume × Overrun Percentage). This helps ensure you have enough concrete to complete the job without running short.