KML Path Length
Drop a KML to visualise paths and estimate route length from the drawn geometry.
By Aryan Khan, Founder & Editor · Updated October 2026
LineString lengths are summed separately; polygon boundaries are excluded and KMZ archives must be extracted first.
How to use KML Path Length
The path is in the file. Measure the file:
Open an uncompressed KML file to display supported placemarks and sum the spherical lengths of LineStrings in kilometres and miles. Separate lines are not joined; polygons are excluded.
- 1Open a KML file; extract KMZ first.
- 2Inspect paths on the map.
What people use KML Path Length for
1. Verifying a published trail KML
Compare a published trail distance with the drawn LineString; differences may reflect sampling, route changes or measurement methods. For GPX tracks, try the GPX Track Distance Calculator.
2. Planning from a drawn route
Someone drew the route in Google Earth and sent the KML. Its length prices the day before the day prices you.
3. Utility and boundary work
Estimate lengths of cable runs or fence lines drawn as LineStrings. These are surface estimates, not survey measurements.
4. Comparing route variants
Open each route variant separately and compare the displayed LineString totals.
Worked examples
A path with several coordinates is measured as the sum of spherical distances between consecutive points. KML tuples use longitude,latitude order.
A hand-drawn path or sparsely sampled track can miss bends. The result measures the supplied geometry, not necessarily the route travelled.
What gets measured
The geometry census behind the length.
| KML content | Measured? | Treatment |
|---|---|---|
| LineString | Yes | Consecutive tuples summed by haversine |
| Polygon boundary | No | Polygon rings are excluded |
| Point | No length | Zero extent by definition |
| gx:Track | Not standard KML geometry | A Google extension — GPX tools own track arithmetic |
Altitude in the tuples is ignored for length: the measurement is surface distance, like the GPX tools — a 10% grade adds only ~0.5% of true slope distance.
How to interpret the result
The most common errors come from using a correct result to answer the wrong geographic question. Keep these points in mind for KML Path Length:
- Keep the original file even after converting: GPX→GeoJSON drops timestamps' context, KML→GeoJSON drops styling, and every pipeline has a lossy edge. Originals are cheap; re-acquisition is not.
- Validate before trusting exports from unfamiliar tools — open them in a local viewer and check feature counts, bounding boxes and a few property rows. A wrong-axis or swapped-coordinate export is far easier to catch on a map than in a spreadsheet.
Limits & appropriate use
File formats support different combinations of geometry, timestamps, properties and styling. Converting between them can lose information, so keep the original and inspect the output before sharing or using it.
Capabilities differ by workspace: check the accepted format and the operations actually offered on this page. Some tools process files locally but may request map tiles or other services over the network; large or specialised datasets may require dedicated GIS software.
- Cadastral/legal formats → jurisdictional land-registry exports.
- Point clouds and rasters → desktop GIS with proper spatial indexes.
- Certified tracks (evidence, insurance) → chain-of-custody originals, untouched.
Data & methodology
Supported KML LineStrings are measured as sums of spherical distances between consecutive coordinates; separate lines are not joined and polygon rings are excluded. KMZ must first be extracted.
For source details, licences and model limitations, see Data Sources and Methodology.
Key terms worth knowing
- GeoJSON
- JSON geographic format; the web-mapping native dialect.
- KML
- XML format from the Google Earth era, with styling and ExtendedData.
Editorial guidance: MapBench explains the method and limitations so the tool can be used as a transparent reference, not as a black-box answer. For legal boundaries, safety-critical routing, surveying, engineering, regulated decisions or official statistics, verify the result with the responsible authority or a qualified professional.
Category: Map Files. Results are intended for everyday analysis and planning unless a page explicitly states otherwise.
Method, assumptions & limits
- This tool’s method
- Supported KML LineStrings are measured as sums of spherical distances between consecutive coordinates; separate lines are not joined and polygon rings are excluded. KMZ must first be extracted.
- Before relying on the answer
- Inspect the accepted file format and the fields reported by this specific tool. Keep a copy of the original file before converting or editing it.
- What the result cannot establish
- File geometry and recorded timestamps can be incomplete. Verify row or point counts and inspect the exported file in your target application.
Coverage: Worldwide. Search, basemap and external data requests may use third-party services; browser-based does not mean every operation is offline. Read the source and licence notes, calculation methodology and privacy policy. If a result looks inconsistent, report a correction with the inputs and mode used.
Frequently asked questions
Clear answers about the calculation, accuracy and appropriate use.
Uploaded?
Parsed in your browser — not stored on MapBench servers.
Is my uploaded map file sent to a server?
Where a page says browser-first or local processing, the file is handled in your browser. Check the individual tool note for any external-service dependency.
What should I do if a file will not load?
Check that the file type is supported, the structure is valid and the file is within the stated size limits. Converting to GeoJSON, GPX, KML or CSV can also help.
Will converting a file preserve every property?
Not always. Geographic formats support different geometry, style and metadata features, so inspect the output before relying on it.
Are Polygon boundaries measured?
No. The total includes supported LineStrings only; polygon rings are excluded.
KML coordinates are lon,lat — really?
Really: KML's tuple order is longitude,latitude[,altitude] — the reverse of GPX and of everyday speech. The tool parses KML's convention natively; most hand-rolled scripts that get KML wrong, get this wrong.
Drawn in Google Earth versus recorded by GPS?
Both are measured from their supplied coordinates. Drawing, GPS noise and sampling can all affect the result.
Closed paths (loops)?
A LineString whose last tuple returns to its first closes the loop in the sum. An unclosed 'loop' measures open — check the file if the total feels one leg short.
Does it follow roads or paths on the ground?
No — straight hops between the file's tuples, the geometry as drawn. Snapping to a path network is a routing engine's job.
Very long lines (flight paths)?
Haversine hops are great-circle segments — a transcontinental LineString sums as the sphere dictates, which is the correct behaviour for a straight-line file.
Empty or single-point LineStrings?
A single-point or empty LineString is not rendered or counted as a line. If the file contains no supported visible placemarks, it will not open.
Related tools and resources
GPX equivalent: the GPX Track Distance Calculator; geometry census: the KML Coordinate Block Counter; see the path: the KML Viewer; GeoJSON lengths: the GeoJSON Length Calculator.
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Sources, methodology & editorial trust
- ✓ Browser-first processing where supported
- ✓ External sources are documented
- ✓ No account required for public tools
- ✓ Review data sources
Calculations are documented with their assumptions, limitations and source context rather than presented as unexplained answers.
Reviewed and maintained by Aryan Khan, Founder & Editor of MapBench.
Part of our gis files hub
KML Path Length sits in the gis files cluster, alongside 64 other tools that answer neighbouring questions with different methods or datasets. It also belongs to the CSV, KML & WKT family.
You may also need
When this answer is only part of the job, these clusters cover the next step.
Read the guide behind this tool
KML vs. GeoJSON vs. GPX: Choosing the Right Map File Format — The practical differences between three common geographic file formats — when to use each, what can be lost in conversion, and how to move between them.