Calculate earthwork cut and fill volume between two cross-sections using the average end area method. Optional prismoidal correction for higher accuracy. Returns cubic yards for road grading and site work estimation.
Total stations and GPS rovers for field cross-section surveys and earthwork as-built verification.
Shop Express Tools →The average end area method is the standard approach for earthwork volume on road and site grading projects. It calculates the volume of earth between two cross-sections by averaging their areas and multiplying by the distance between them.
| Material | Shrinkage Factor | Meaning |
|---|---|---|
| Sandy soil | 0.85–0.90 | 1 bank CY = 0.85–0.90 compacted CY of fill |
| Common earth | 0.80–0.85 | 1 bank CY = 0.80–0.85 compacted CY of fill |
| Clay (medium) | 0.75–0.80 | 1 bank CY = 0.75–0.80 compacted CY of fill |
| Clay (heavy) | 0.70–0.75 | 1 bank CY = 0.70–0.75 compacted CY of fill |
| Gravel | 0.90–0.95 | 1 bank CY = 0.90–0.95 compacted CY of fill |
| Rock (blasted) | 1.30–1.40 | Rock expands — 1 bank CY = 1.30–1.40 loose CY |
Bank measure = in-place volume before excavation. Apply shrinkage factor when using cut material as compacted fill.
On public works contracts, earthwork is typically paid by the cubic yard of bank measure. The contractor submits monthly pay quantities showing the volume of cut and fill completed since the last pay estimate. Field verification of earthwork volumes requires taking current cross-sections in the field and comparing them to the design cross-sections to calculate the as-built volumes.
When design quantities and field quantities differ (due to ground conditions, design revisions, or construction changes), the difference must be documented with field cross-section data to support a change order. Running station-by-station calculations with this tool — or with Sitemark's field documentation platform — creates the audit trail needed for quantity change order support.
Earthwork volume between two cross-sections is calculated using the average end area method: Volume (CY) = ((A1 + A2) / 2) × L / 27. Where A1 and A2 are the cross-section areas in square feet and L is the distance between sections in feet. Divide by 27 to convert cubic feet to cubic yards. For higher accuracy, use the prismoidal formula: Volume (CY) = (L / 6) × (A1 + 4×Am + A2) / 27, where Am is the midpoint cross-section area.
Cut is material removed to lower the existing ground to design grade — the ground is higher than the design, so it is excavated. Fill is material added to raise the existing ground to design grade — the ground is lower than the design, so soil is placed and compacted. On grading and road projects, cut and fill are tracked separately because they have different costs, equipment needs, and mass haul implications. Cut material may be used as fill elsewhere on the project.
A cross-section area is the area of a vertical slice through the earthwork at a specific location (station) along the project alignment, measured in square feet. The cross-section shows the shape of the cut or fill required to transition from existing ground to design grade at that station. Cross-section areas are typically taken from road design plans at 50-foot or 100-foot intervals. The area can be calculated by coordinate method, planimeter, or design software output.
The average end area method is accurate to within 1–5% of the true volume in typical road terrain. It overestimates volume when cross-section areas change significantly from section to section. The prismoidal formula is more accurate and should be used when cross-sections change by more than 20% between consecutive stations. For bid estimation on most highway and site grading projects, average end area accuracy is adequate.
Yes, when using cut material as compacted fill. The shrinkage factor accounts for volume loss during compaction. Sandy soil: factor 0.85–0.90 (one bank cubic yard of cut produces 0.85–0.90 compacted cubic yards of fill). Clay: 0.75–0.85. The shrinkage factor is applied in mass haul analysis to convert bank measure cut quantities to compacted fill equivalents. Failing to apply shrinkage leads to mass haul imbalances and material shortfalls on the fill side.