About
About North Pinnacle
North Pinnacle is a small set of free tools for working with positions on the earth: converting between coordinate formats, measuring distances and bearings, finding destination points and reading grid references. It is meant for hikers and climbers checking a waypoint, search-and-rescue volunteers reading out an MGRS reference, students meeting map projections for the first time, and developers who need a quick, trustworthy answer.
How it works
Everything is calculated in your browser. The site has no server code and never asks for your location: the browser's location feature is switched off for these pages, so positions only come from what you type. Once a page has loaded it keeps working offline.
Datum and methods
- Datum: WGS84 throughout (semi-major axis 6,378,137 m, flattening 1/298.257223563), the datum GPS reports. Positions from older national datums can differ by tens or hundreds of metres.
- UTM and MGRS: Krüger's series to sixth order as given by Karney (2011), with the zone exceptions and lettering from the NGA's Universal Grids standard.
- Ellipsoidal distances, bearings and destinations: Karney's geodesic algorithms (2013) through GeographicLib, with Vincenty's formula shown alongside.
- Spherical formulas: as set out by Chris Veness on Movable Type Scripts, with the mean earth radius of 6,371,008.8 m.
Each method is checked by automated tests against published worked examples and against independent libraries on thousands of random points.
Limits
UTM and MGRS are not defined beyond 84°N and 80°S, where the UPS grid takes over; this site does not convert UPS. Bearings are true bearings: allow for magnetic declination when using a compass. Treat the results as a planning aid, not a replacement for a map, a compass and local knowledge in the field.