English: Length of one degree (black), minute (blue) and second (red) of latitude and longitude in metric (upper half) and imperial (lower half) units at a given latitude in WGS84 by CMG Lee. For comparison, dotted lines denote corresponding lengths assuming a spherical Earth of IUGG mean radius (R₁ = 6,371.0088 km). For example, the green arrows show that Donetsk (green circle) at 48°N has a Δ_long of 74.63 km/deg, 1.244 km/arcmin, 20.73 m/arcsec etc and a Δ_lat of 111.2 km/deg, 1.853 km/arcmin, 30.89 m/arcsec etc. The background bitmap is from http://commons.wikimedia.org/wiki/File:Equirectangular_with_Tissot%27s_Indicatrices_of_Distortion.svg .