Terrain Profile
This tool draws an elevation profile chart along a path you define. Click two or more points on the interactive map to lay out a route — a hiking trail, a road section, a pipeline corridor — then click Generate elevation profile.
The tool takes 40 evenly spaced samples along your path and looks up each one's elevation via the free Open-Elevation API, then renders a profile chart with minimum and maximum elevation, total climb, total descent and the path's great-circle distance. Elevations are SRTM-based at roughly 30 m resolution: good for route planning, not for engineering. If the elevation service is unreachable, the tool says so plainly instead of showing fake data.
Terrain profiles are built from public elevation data and are approximate. They are for planning and visualization only — verify conditions on site before relying on them for construction, drainage work, or outdoor activities.
Click on the map to add path points (drag to pan). You need at least 2 points — 40 evenly spaced samples are taken along the path and looked up via the Open-Elevation API.
How to use this tool
Click to add each waypoint of your route (drag to pan). Add at least 2 points; use Undo or Clear to adjust.
Click Generate elevation profile. Forty samples are taken along the path and their elevations are fetched from the Open-Elevation API.
Study the elevation chart and the min/max, total climb, total descent and distance figures to judge the route's difficulty.
What people use this tool for
Trace a planned trail to see total ascent and the steepest sections before committing to it.
Compare candidate road routes by total climbing to pick one that matches the group's fitness.
Get a quick elevation overview along a proposed pipeline, cable or track alignment for early-stage planning.
How it's calculated
Waypoints are sampled at 40 equal-distance positions by interpolating along cumulative Haversine segment lengths. Elevations are fetched in one POST to https://api.open-elevation.com/api/v1/lookup with the 40 locations. Total climb is the sum of positive elevation differences between consecutive samples, descent the sum of negative ones; min/max are over the samples. The chart is an inline SVG polyline scaled to the sample range. Path distance is the Haversine sum between waypoints.
Related tools and resources
Frequently asked questions
Where do the elevations come from?
The free Open-Elevation API, which serves SRTM-based elevation data at roughly 30-metre resolution. That is plenty for route planning but too coarse for construction or flood-risk engineering.
Why 40 sample points?
Forty evenly spaced samples capture the shape of most routes while keeping the lookup request fast and within the free API's limits. Very twisty micro-terrain between samples will be smoothed over.
What does 'elevation service unavailable' mean?
The tool could not reach the Open-Elevation API — your connection may be down or the free service may be rate-limiting. Check your connection and retry; your path points are kept so you don't have to redraw.
Is total climb the same as max minus min?
No. Total climb sums every uphill section along the path, so a rolling route can climb far more than its highest-minus-lowest difference. The tool reports both figures separately.
Data sources & methodology
- OpenStreetMap — Base map tiles.
- Leaflet — Interactive map rendering library.
- Open-Elevation — Free elevation lookup API (SRTM-based).