Pure Python MGRS <-> latitude/longitude conversion with no external dependencies.

This repository provides a single-file library for:

• converting WGS84 latitude/longitude to MGRS
• converting MGRS back to latitude/longitude
• running round-trip regression tests
• benchmarking conversion throughput

• Pure Python: no C extensions, compiled wheels, or third-party packages
• Small surface area: one file, direct functions, easy to vendor
• Fast enough for bulk conversion workloads

Install from PyPI:

python3 -m pip install mgrs-pure-python

Or clone the repository and import mgrs.py directly:

git clone https://github.com/aydink/mgrs.git
cd mgrs

No dependency installation is required.

To install it as a local package with the CLI entrypoint:

python3 -m pip install .

from mgrs import latlon_to_mgrs

mgrs_ref = latlon_to_mgrs(41.0082, 28.9784, precision=5)
print(mgrs_ref)
# 35TPF6637041552

from mgrs import mgrs_to_latlon

lat, lon = mgrs_to_latlon("35TPF6637041552")
print(lat, lon)
# 41.008200115451004 28.97839994400028

from mgrs import latlon_to_mgrs, mgrs_to_latlon

lat, lon = 40.6892, -74.0445
mgrs_ref = latlon_to_mgrs(lat, lon, precision=5)
lat2, lon2 = mgrs_to_latlon(mgrs_ref)

print(mgrs_ref)
print(lat2, lon2)

If installed from PyPI, use:

mgrs --lat 41.0082 --lon 28.9784 --precision 5

The examples below also work directly from the repo checkout:

python3 mgrs.py --lat 41.0082 --lon 28.9784 --precision 5

python3 mgrs.py --mgrs 35TPF6637041552

python3 mgrs.py --test

python3 mgrs.py --benchmark --count 1000000 --precision 5

python3 mgrs.py --benchmark --count 100000 --precision 5 --validate

• latlon_to_mgrs(lat, lon, precision=5) -> str
• mgrs_to_latlon(mgrs) -> tuple[float, float]
• benchmark_mgrs(n=1_000_000, precision=5, validate=False) -> None
• test() -> None

• Coordinates use the WGS84 datum.
• MGRS precision is controlled with precision=1..5.
• Decoding returns the center of the represented MGRS cell.

MIT. See LICENSE.

This repository includes a GitHub Actions workflow for PyPI Trusted Publishing. After configuring the project on PyPI, publishing a GitHub release will upload the package automatically.