How to Use the Cut and Fill Earthwork Balance Calculator
A grading plan works best when material excavated on site is used to build the embankments on the same site. Soil does not keep the same volume through that trip, though: it swells when it is dug and shrinks when it is compacted, so comparing raw cut and fill quantities always misleads. This calculator applies the volume change factors and reports the real surplus or shortage.
Three measures are used in American earthwork. Bank cubic yards describe material in place, loose cubic yards describe it in the truck, and compacted cubic yards describe it after placement and rolling. A swell of 25% means one bank yard of common earth fills 1.25 loose yards in the haul unit, while a compaction factor of 0.90 means the same bank yard becomes only 0.90 yard of finished embankment.
The cut required to build a given fill therefore equals the fill quantity divided by the compaction factor. Comparing that number to the available cut shows whether the job balances. A surplus has to be hauled off or wasted on site, a shortage has to be imported from a borrow pit, and because hauling happens in the loose state the difference is multiplied by the swell factor to size the trucking.
Volume change factors vary with moisture content, the degree of compaction specified and the test method, so use the values given in the project geotechnical report or specifications when they are available. Quantities here support planning level takeoffs; haul distance, equipment match and overhaul payment terms have to be priced separately.
Frequently Asked Questions
The compaction factor converts bank material into finished embankment, so it sets how much cut a fill requires. The swell factor describes the loose volume in the haul unit, so it sizes truck counts and haul cycles.
Ordinary soil loses roughly ten percent of its volume when it is compacted. With a factor of 0.90, building 10,000 compacted yards takes about 11,111 bank yards, so quantities that appear balanced on paper still come up short in the field.