When to use it

Planning a driveway, a track, a pipe run, a fence line or a race.
Checking the climb on a walk, a ride or a run.
Seeing whether water will flow the right way along a proposed drain.

How to use it

Open Elevation Profile and tap out the line, corner by corner. Undo removes the last point.
Finish the line. The profile chart appears in the panel.
Hover the chart to read distance and elevation at any point, and download the data.

How it works

The line is sampled at close, even spacing and the LiDAR bare-earth model is read at each sample, interpolating between cells. Ascent and descent are the sums of the rises and falls between samples; gradient is rise over run between them.

Reading the results

Gradient is in percent: 10 % is 1 m of rise for every 10 m along. Driveways over about 16 % are hard for cars; 20 % is the usual council limit.

Total ascent and descent count every small rise, so a rolling line shows more climb than the difference between its ends.

Limits and warnings

Lines up to 25 km.
Where 1 m LiDAR has not been flown the tool falls back to the national 8 m elevation model, and the result says what share came from the fallback. The 8 m model was interpolated from 20 m map contours and is not fit for site-scale decisions.
Bare ground only. A bridge or a culvert shows as the valley beneath it.

Data and attribution

Results come from the LINZ national 1 m LiDAR bare-earth elevation model, read in your browser, with the national 8 m model filling any gaps. Tools that use the surface model (Sunlight, Viewshed, Object Heights) read the matching LiDAR surface tiles.

Elevation and cadastral data is sourced from the LINZ Data Service and licensed for re-use under the Creative Commons Attribution 4.0 International licence. Copyright in each LiDAR survey belongs to the body that commissioned it — a regional or district council, Waka Kotahi, NIWA and around thirty others — rather than to LINZ, which hosts and processes the national dataset. Every file exported from this site names the licensors whose surveys cover the area, and anything you publish from those files carries the same attribution requirement. See https://www.linz.govt.nz/products-services/data/licensing-and-using-data/attributing-elevation-or-aerial-imagery-data

Measure — Measures both the flat map distance and the true distance over the ground along a line, which is longer on steep terrain.
Route Explorer — Finds a route between two points that favours gentle grades and stays under a maximum grade you set, and shows its elevation profile.
Sightline — Checks whether one point is visible from another, and if not, where the view is first blocked and by how much.
Elevate a File — Adds accurate ground elevation to the coordinates in a GPX, KML, GeoJSON, JSON or CSV file you already have, replacing missing or noisy GPS altitude.

Guides

Elevation Profile