Compute cut and fill on the real terrain

Draw your platform, pick its elevation: GeoAlt confronts the design with the IGN-measured relief and computes the quantities.

The earthworks budget lives on volumes: too much cut means hauling; too much fill means importing. The calculation is only worth something if it rests on the real terrain — not an approximated relief. GeoAlt measures the existing ground by LiDAR or RGE ALTI, then confronts your platform with the measured relief.

What usually gets in the way

An approximate base terrain

A hand-interpolated DEM or one from an old plan distorts volumes by tens of percent on rolling ground.

Quantities recomputed at every iteration

Moving the platform by 20 cm should re-read the volumes in a minute, not restart a two-day study.

Opaque cut/fill balances

Without a thickness map, you cannot see where cut accumulates or fill is missing: decisions are made blind.

The GeoAlt computation

Existing ground measured, not estimated
The DEM comes from LiDAR HD (ground classes) or RGE ALTI: the starting relief is the one measured by the IGN, with its date and source.
Platform at a free or sloped elevation
The project platform sits at a constant elevation or follows a slope: the computation handles both configurations.
Volumes and thickness map
Cut and fill are quantified in cubic metres, and the thickness map shows where to dig and where to fill, colour by colour.
Instant iterations
Changing the platform elevation re-reads the volumes immediately: the cut/fill balance is optimised live.
Compute cut and fill on the real terrain
The public demo computes the quantities of a platform on a real parcel.

Try the volume computation

The public demo computes the quantities of a platform on a real parcel.

Open the demo

Deliverables

  • Cut / fill volumes in m³
  • Thickness map overlaid on the orthoimagery
  • DXF of the platform and the terrain
  • PDF report with the computation assumptions

Stated technical limits

  • Volumes follow the source model resolution: on very rugged ground, a LiDAR DEM is markedly more faithful than RGE ALTI.
  • The computation does not see low grass and moss: on meadow, the stripping thickness remains the designer’s assumption.
  • Quantities are design estimates: they do not replace the contractor’s execution measurements.

Frequently asked questions

How accurate are the volumes?

Accuracy depends on the base terrain: with a LiDAR HD DEM, volumetric error on open ground is on the order of a few percent. Under dense vegetation, the covered ground is interpolated — uncertainty rises.

Can the platform be sloped?

Yes: the platform follows a slope and direction defined by the designer, or stays at a constant elevation.

Can I compare several scenarios?

Yes: every platform elevation or shape re-reads the volumes immediately — the cut/fill balance is optimised live.

Is the computation charged on every try?

No: iterations over the same area are not re-charged — only the final exported result is billed, once.

Compute your earthwork quantities

Draw the platform, pick the elevation, read the volumes: all on the real IGN terrain.

Open the application