Measure your yard from above

How we work it out

The photo is Esri's World Imagery, which stitches together recent aerial and satellite photos, sharp to about a foot on the ground in most US towns.

Lengths are measured along the curve of the Earth between the points you click, and areas on a flat projection centered on your shape. At yard scale the math is far more exact than the photo, so the photo is the limit: expect lengths within a foot or two and areas within about 5% when the edges are clear.

Trace where things meet the ground. Roofs lean in aerial photos and trees hide edges, so a house traced by its roofline comes out shifted. The address search goes to the US Census Bureau's public geocoder and isn't stored. Your drawing lives only in this page's link and your browser.

In Arkansas, Connecticut, Hawaii, Maryland, New Jersey, North Carolina, Utah, Vermont, Virginia and Washington, DC, in most of Colorado, and in King County (WA), the Portland and Twin Cities metros, Indianapolis, Oakland County (MI), Rochester (NY), Sacramento County (CA), Ada County (ID), DeKalb County and Johns Creek (GA), Sioux Falls (SD) and Fargo (Cass County, ND), a Property lines button draws the parcel lines over the photo. They come straight from each government's public map service, under terms that allow reuse, and they're approximate: good for finding roughly where your lot ends, not for setting a fence. A survey settles that.

Set something down. Sheds, hot tubs, patio sets, grills, fire pits, playsets' safe play areas and cars drop onto the photo at their makers' sizes, the same ones our guides use. Drag and turn them. Grills and fire tables draw their makers' clearance as a dashed line; a wood fire pit checks the fire code's 25 ft against the areas you've drawn. With property lines on, each one shows its distance to the lot line, and against your town's setback if you put it in.

Ground slope. On any line you draw, Get the ground slope asks USGS's Elevation Point Query Service for the bare-ground height every 5 ft or so (up to 20 points), from the 3D Elevation Program. That's 1 m data where there's lidar and about 10 m elsewhere; the result says which. USGS elevation data is free and public domain.