Civil Engineering · Surveying
Land Area & Earthwork Volume
Triangle and trapezoid land area, slope grade, and cut/fill earthwork volume by the average end area method.
Standard method — stated scope limits apply
Triangle Area
Trapezoid Area
Slope
Cut & Fill Volume (Average End Area)
Choose a calculation above.
About This Calculation
Earthwork quantity calculation — how much soil must be cut or filled to grade a site to its design elevations — typically uses the average end area method: cross-sectional areas at regular survey stations are averaged between consecutive stations and multiplied by the station spacing to estimate volume, a practical approximation that works well when ground profile doesn't change too abruptly between survey points. Getting cut/fill quantities right matters directly for project cost estimation and for balancing cut material against fill needs to minimize expensive material haul-off or import.
Frequently Asked Questions
Why use the average end area method instead of exact integration of the ground surface?
The actual ground surface between survey stations is never perfectly known — average end area gives a practical, repeatable estimate from the CROSS-SECTIONS actually surveyed, and its accuracy improves with closer station spacing, which is exactly why survey stations are placed more closely together where the ground profile changes more rapidly.
What does "balancing" cut and fill actually mean for a project?
It means arranging the site grading design so that cut material removed from high areas is reused as fill in low areas, minimizing the volume that must be hauled off-site (excess cut) or imported (shortfall needing fill from elsewhere) — since hauling earth off-site or importing it are both genuinely expensive, a well-balanced grading design meaningfully reduces project earthwork cost.
Why does soil "swell" and "shrink" factor into earthwork volume calculations?
In-place (bank measure) soil volume changes when excavated and re-compacted — most soils swell (increase in loose, excavated volume) when first dug, then shrink below their original bank volume once recompacted as fill, because compaction achieves a different density than the soil’s natural in-place state; earthwork estimates must apply the correct swell/shrink factor for the specific soil type or genuinely misjudge how much material is actually needed.