Length of a Degree of Latitude and Longitude Calculator
How many kilometres one degree of latitude and one degree of longitude span at your latitude, and how many degrees a given distance is, on the WGS84 ellipsoid.
Results
The dashed line marks the value you entered.
What this tool does
A degree of latitude is almost constant — 110.6 km at the equator and 111.7 km at the poles, because the Earth is slightly flattened — but a degree of longitude shrinks with the cosine of the latitude, from 111.3 km at the equator to nothing at the poles. That is why a square drawn in degrees is not square on the ground, and why a search radius or bounding box for a map should be converted at the right latitude. At 40° N, one degree of longitude is about 85.4 km.
Formula
1° latitude = (π ÷ 180) × a(1 − e²) ÷ (1 − e² sin²φ)^1.5 · 1° longitude = (π ÷ 180) × a cos φ ÷ √(1 − e² sin²φ) (WGS84)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
la | Latitude | ° |
ds | Distance you want to turn into degrees | km |
LO | Length of 1° of longitude here | km |
LA | Length of 1° of latitude here | km |
DA | That distance in degrees of latitude | ° |
DO | That distance in degrees of longitude | ° |
PL | Length of the whole parallel | km |
Worked example
- Latitude40 °
- Distance you want to turn into degrees10 km
- Length of 1° of longitude here85.394 km
- Length of 1° of latitude here111.035 km
- That distance in degrees of latitude0.09006 °
- That distance in degrees of longitude0.11710 °
- Length of the whole parallel30,742 km
Limitations
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.