openlayers/examples/measure.html

Build tools and sources for developing OpenLayers based mapping applications

---
layout: example.html
title: Measure
shortdesc: Using a draw interaction to measure lengths and areas.
docs: >
  <p>The <code>ol.Sphere.getLength()</code> and <code>ol.Sphere.getArea()</code>
  functions calculate spherical lengths and areas for geometries.  Lengths are
  calculated by assuming great circle segments between geometry coordinates.
  Areas are calculated as if edges of polygons were great circle segments.</p>
  <p>Note that the <code>geometry.getLength()</code> and <code>geometry.getArea()</code>
  methods return measures of projected (planar) geometries.  These can be very
  different than on-the-ground measures in certain situations — in northern
  and southern latitudes using Web Mercator for example.  For better results,
  use the functions on <code>ol.Sphere</code>.</p>
tags: "draw, edit, measure, vector"
---
<div id="map" class="map"></div>
<form class="form-inline">
  <label>Measurement type &nbsp;</label>
  <select id="type">
    <option value="length">Length (LineString)</option>
    <option value="area">Area (Polygon)</option>
  </select>
</form>