How to measure a distance on the map
- Find the place: type a town or paste coordinates (for example
39.7392, -104.9903) in the search box and pick it, or drag and zoom the map yourself. - Leave the mode on Distance and click or tap the start of the route.
- Keep tapping at every bend. Each tap adds a point and the total grows; it is shown under the map and next to the last point.
- Drag a point to move it. Tap the small dot halfway along a segment to add a point there, which is the quickest way to bend a straight segment around a corner.
- Read every segment, the running total and the compass bearing of each leg in the table under the result.
The distance follows exactly the points you place, in straight lines between them. Two points give the straight-line distance between two places, as the crow flies. To measure along a road, river or trail, put a point at each bend: the more closely the points follow it, the closer the total is to the real length. Back to start adds the first point again to close a loop, and Mark every mile (or kilometre) numbers each mile along the path.
How to measure an area and its perimeter
Switch to Area and perimeter, then tap each corner of the field, lot, roof, lake or park, in order around its edge. After the third point the outline closes by itself and the area appears in the unit you choose: acres, hectares, square feet, square metres, square kilometres or square miles, with the other common units beside it. The perimeter and each side's length are listed too, and Label each side on the map writes the lengths on the drawing.
If the outline crosses itself, like a figure eight, it has no single area, and the page says so: drag a point until the sides no longer cross. For a fence, open Fence posts and type the largest gap you want between posts; it counts the posts, with one at every corner.
A drawing can switch between the two modes at any time: draw the edge of a park as a path to get the length of its boundary walk, then switch to area to see how big it is.
How accurate is it?
The measuring itself is exact. Every segment is a geodesic, the shortest path over the WGS84 ellipsoid that GPS and web maps use, measured with Vincenty's formulae, so a long line of 3,000 miles is right to the metre, not just a flat-map estimate. Areas follow the curve of the Earth as well. We checked both against GeographicLib, the reference library for geodesics, on shapes from a 300 m² garden to an eighth of the planet, and they agree to better than one part in a million.
What limits the result is where the points sit. Zoom in before you place the corners of something small: at the closest zoom one pixel is well under a metre, while zoomed out over a county a single pixel can be 50 metres. Map images can also be shifted by a metre or two from the ground, and a property's legal boundary is set by its survey and deed, not by a map, so treat the numbers as a careful estimate for planning, buying seed or fencing, and comparing places.
Units
Pick the distance unit (miles, kilometres, feet, metres, yards or nautical miles) and the area unit separately. One acre is 43,560 square feet, about 4,047 m², and 640 acres make a square mile; one hectare is 10,000 m², about 2.47 acres. Feet here are international feet of exactly 0.3048 m. On January 1, 2023 the international foot superseded the US survey foot for all applications except historic and legacy data; the two differ by about 2 parts in a million.
Undo, keyboard and exports
Undo and Redo step back and forth through every added, moved or deleted point (Ctrl or ⌘ + Z and Ctrl or ⌘ + Shift + Z on a keyboard). To work by keyboard alone, focus the map, move it with the arrow keys, zoom with + and −, and press Enter to add a point under the crosshair in the middle; Delete removes the last point. To move a point, select its number in the table, which centres the map on it, pan to the new spot and press Enter on the map.
GPX downloads the path or outline as a track for Garmin, Strava, Komoot and most GPS apps; KML opens in Google Earth; GeoJSON goes into QGIS, ArcGIS or a web map, with the length or area as properties. Copy results copies the numbers with every point's coordinates, and Share result copies a link that opens the same drawing, which holds only the points you drew.
Related tools
To draw a circle of a set distance around a town or ZIP code instead, and see the towns inside it, use the radius map. Measured a room or a floor rather than land? The flooring calculator and paint calculator turn the size into materials to buy. And to see where a photo was taken from its GPS data, open it in the EXIF viewer.