Degrees, metres and area scale calculator

1. Length of a degree at your latitude

Latitude (degrees, south negative) A length in degrees (for example a buffer) A length in metres

Result (WGS 84 ellipsoid)	Value
One degree of latitude	-
One degree of longitude	-
Your degree length, north-south	-
Your degree length, east-west	-
Your metres as degrees of latitude	-
Your metres as degrees of longitude	-

2. Area scale: what a wrong CRS does to a site area

True site area (ha; default 76.31 is our synthetic site)

Result at the latitude above	Value
Web Mercator (EPSG:3857) planar area factor	-
Same site measured in Web Mercator	-
Degree method factor (square degrees × 111,320 squared)	-
Same site by the degree method	-

Length series and the Web Mercator factor are standard formulas we coded, not taken from an opened document; we checked them against pyproj. The Web Mercator factor allows for EPSG:3857 using geodetic latitude as if on a sphere. The degree method uses 111,320 m for both axes, a common rule of thumb. All are for a small site at one latitude; a very large site needs a proper geodesic calculation. Local projected CRSs (UTM zone, state plane or national grid) and equal-area CRSs keep area errors small. Number entry: a single dot is a decimal point; a comma followed by exactly three digits is a thousands separator (10,000); write 1,5 or 1.5 for decimals; 1.000 is rejected as ambiguous. Not for survey or legal boundaries.