Degrees to Kilometers Converter

How to Use the Degrees to Kilometers Converter

Enter the latitude at which you want to compute the conversion, and the number of degrees you want to convert. The calculator returns how many kilometers and miles one degree of latitude and one degree of longitude corresponds to at that latitude, plus the converted distance for the number of degrees you entered. Set the reference latitude to wherever you are working: 0 for the equator, 45 for mid-latitudes, or up to 90 as you approach the poles. Longitude results shrink toward zero as latitude approaches the poles.

Why Latitude and Longitude Spacing Differ

Lines of latitude run parallel to the equator and are evenly spaced from pole to pole, so one degree of latitude is almost the same distance everywhere on Earth — about 111.32 km. Lines of longitude, by contrast, all meet at the poles and splay out at the equator. At the equator they are exactly the same spacing as lines of latitude, but as you move toward the poles they get closer together. Mathematically, one degree of longitude at latitude phi is about 111.32 × cos(phi) km, which reaches zero at the poles. This asymmetry is why maps of polar regions look so different from equatorial maps and why it is impossible to make a flat map of the entire Earth without distortion.

Precision in GPS Coordinates

A common practical question is: how many decimal places of latitude and longitude do I need for a given accuracy? Here is a quick reference. At any latitude, 1 decimal place of latitude is about 11 km. 2 decimal places is about 1.1 km. 3 decimal places is 111 m. 4 decimal places is 11 m. 5 decimal places is 1.1 m. 6 decimal places is 11 cm. Longitude precision is multiplied by cos(latitude), so at 45 degrees latitude the longitude precision is about 70 percent of the latitude precision. Six decimal places is the practical limit for most consumer GPS devices, and is usually more than enough for navigation, surveying, and mapping.

The Oblate Spheroid Earth

Real Earth is not a perfect sphere — it is flattened at the poles and bulges at the equator, giving an equatorial radius of about 6378 km and a polar radius of about 6357 km, a difference of roughly 21 km or 0.3 percent. The consequence for degree conversion is that one degree of latitude is actually slightly shorter near the equator (about 110.57 km) than near the poles (about 111.69 km). This calculator uses the average value of 111.32 km per degree of latitude, which is accurate to about half a percent everywhere. For survey-grade work, use the WGS-84 ellipsoid through a geodetic library, which applies the correct local radius at each latitude.

Frequently Asked Questions

How many km is 1 degree of latitude?

Approximately 111.32 km everywhere on Earth. It varies by less than half a percent between the equator and the poles.

How many km is 1 degree of longitude?

111.32 × cos(latitude) km. At the equator, 111 km. At 45°, about 79 km. At 60°, about 56 km. Zero at the poles.

When would I use this?

GPS precision estimates, GIS grid spacing, map scale calculations, drone flight planning, and teaching geographic concepts.

Is Earth really spherical?

No. Earth is an oblate spheroid with a 21 km flattening. The spherical approximation is accurate to about 0.5 percent for degree-to-distance conversions.

How does this relate to GPS accuracy?

5 decimal places of coordinates ≈ 1.1 m. 6 decimal places ≈ 11 cm. Beyond 6 places is finer than most consumer GPS can actually measure.