Format a coordinate
Writes a latitude and longitude as decimal degrees, DMS, or DDM with the precision you choose, and tells you what that precision means on the ground.
40°26'46.000"N 79°58'55.999"W, precise to about 0.0308 m on the ground.
- Latitude resolution
- Longitude resolution
Provenance
- Computed by
- geodesy.parse.format 1.0.0, core 0.1.0
- Model
- Rounding carried across components; resolution from the WGS 84 radii of curvature
- Accuracy
- Exact formatting; resolution is the ground size of one unit in the last place
- Notes
- None
- Cites
- International Organization for Standardization, Geographic Point Location, ISO 6709
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Rounding carried across components; resolution from the WGS 84 radii of curvature
Accuracy: Exact formatting; resolution is the ground size of one unit in the last place
When to use this: Use this to write a position the way a form, a chart or a colleague wants it -- decimal degrees, degrees and decimal minutes, or degrees minutes seconds -- at a precision you choose, and to find out what that precision is actually worth on the ground before you decide how many digits to keep.
Limitations: The resolution reported is the ground size of one unit in the last place, not the accuracy of the number: a coordinate printed to six decimals is not thereby good to eleven centimetres. Longitude resolution follows the cosine of the latitude, so the same number of digits means different distances at different latitudes, and at the pole it means nothing at all. Rounding is carried across the components, so a value a hair under a whole degree prints as that degree rather than as fifty-nine minutes sixty seconds.
Worked example: Pittsburgh in DMS. Source: Exact conversion of 40.446111°, -79.982222°.
You enter
- Latitude
- 40.446111 deg
- Longitude
- -79.982222 deg
You get
- Formatted
- 40°26'46.000"N 79°58'55.999"W
- Latitude resolution
- 0.0308 m
- Longitude resolution
- 0.0236 m
Review: Not yet independently reviewed by a geodesist.
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 21 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Geographic Point Location, ISO 6709, International Organization for Standardization, ISO 6709:2022. Annex D (degrees, minutes, and seconds notation). Paid only.