Cut and fill calculator
Grid the site, enter both surfaces, see what moves and where.
[ 1 · Site ]
[ 2 · Surfaces ]
The average of the ground as it is now, on your datum.
Finished grade for the pad.
One average gives one depth, so Quick returns cut or fill, never both. A site with high and low ground needs Grid.
[ 3 · Earth movement ]
200′ × 150′
Enter the existing and proposed elevations. The section draws as you type.
[ 4 · Quantities ]
Cut
—
both elevations at four corners
Fill
—
both elevations at four corners
Net export
—
a computed cut and fill
- Export, as hauled
- Needs a swell factor
- Bank volume the fill consumes
- Needs a shrinkage factor
- Truck loads
- Needs swell and a truck capacity
- Weight
- Needs a loose density
The grid method approximates: it assumes the ground runs straight between nodes, so it cannot see a swale or a ridge that falls between them, and it is not a surface-to-surface computation. A tighter grid is what makes it better.
How this is calculated
The site is divided into a rectangular grid. At every node the existing elevation and the proposed elevation are recorded, and their difference is the depth of cut — positive — or fill — negative — at that point.
Each cell sits between four nodes. Its volume is the average of its four corner depths times its plan area, which is the average-end-area method applied in two directions. Cut and fill are accumulated separately across the site, so a cut cell never cancels a fill cell: that material still has to be dug, moved and placed.
A node with either elevation missing makes its cells unusable, and those cells are skipped rather than treated as flat ground. Assuming a blank elevation is zero would invent level terrain and understate the job.
- Depth at a node
existing elevation − proposed elevation
Positive is cut, negative is fill. Both surfaces must be known at the node.
- Cell area
spacing across × spacing down
Cells sit between nodes, so a 5 × 5 grid of nodes gives 4 × 4 cells.
- Cell volume
mean of four corner depths × cell area ÷ 27
Average end area, in two directions. Divided by 27 for cubic yards.
- Net
total cut − total fill
Positive means material leaves the site; negative means it has to be brought in. Both are bank volumes.
- Export as hauled
net bank volume × (1 + swell)
What actually rides in the truck. Needs a swell factor for your material.
- Bank volume the fill consumes
compacted fill ÷ (1 − shrinkage)
A cubic yard of cut does not make a cubic yard of compacted fill. Needs a shrinkage factor.
What it does not know
- The grid method approximates. It assumes the ground varies evenly between nodes, so a swale or ridge falling between them is invisible to it, and it cannot represent a breakline at all. Tighten the grid where the ground moves.
- A cell whose corners straddle grade averages its cut against its fill, so both are understated there. The calculator counts those cells and tells you how many — the fix is a tighter grid across the daylight line, not a different formula.
- This is not a surface-to-surface computation and does not claim to be one. Contour or triangulated-surface takeoff is a different method with different data requirements.
- The results are bank volumes. Loose volume for hauling and compacted volume for fill need swell and shrinkage factors for your material, which you supply.
- Topsoil stripping, subgrade preparation and over-excavation are separate quantities not included here.