Resources & Guides

Learn what EPSG codes are, why they are essential for GIS and mapping, and understand common codes like EPSG:4326, EPSG:3857, and EPSG:27700.

Learn the most common coordinate formats including DD, DMS, DDM, UTM, UK Grid and UK E/N, with examples and easy conversion using CoordinateMapper.

Understand the difference between coordinate formats, systems, projections, and datums, including practical examples such as WGS84 vs OSGB36.

Latitude and longitude made simple: what they mean, the formats they come in (DD, DMS, DDM), how GPS reads them, plus a free tool to convert any coordinate instantly.

Learn how Easting and Northing grid coordinates work, why they use metres, how they relate to British National Grid, and how to convert them to lat long.

Learn how geographic and projected coordinate systems work, why the same place has different values in each, and how to avoid conversion mistakes.

Learn why flat maps distort the Earth, how projections like Transverse Mercator and UTM work, and why projected coordinates differ from lat long.

Learn how many decimal places you need, the difference between precision and accuracy, and how to choose the right detail level for GPS, GIS, and surveys.

Learn how UTM coordinates work, what zone numbers and Easting/Northing values mean, and when to use UTM over latitude and longitude.

Learn how UK Grid references work, what the two-letter prefix and digits mean, how precision scales with digit count, and how to convert to GPS.

Learn how MGRS works, what grid zones, square letters, and digits mean, how it relates to UTM, and how to convert MGRS coordinates.

Understand the practical difference between WGS84 and OSGB36, why coordinates shift by up to 120 m between them, and how to convert correctly.

Learn what the State Plane Coordinate System (SPCS) is, how its zones, FIPS codes, projections, and units work, and when to use it instead of UTM or lat/long.

Find your current GPS coordinates instantly in every format - Decimal Degrees, DMS, DDM, UTM, MGRS, and UK Grid. Free, no install, works on phones and laptops.

Free address to coordinates converter. Enter an address, place name, or postcode to get GPS coordinates in DD, DMS, DDM, UTM, MGRS, UK Grid, and State Plane, plus reverse lookup.

Step-by-step guide to converting UTM, DMS, UK Grid, Easting/Northing, or DDM into a Google Maps-friendly lat/long format. Avoid common mistakes.

Complete guide to converting British National Grid references to GPS lat/long, including OSGB36-to-WGS84 datum handling and common mistakes to avoid.

Practical guide to fixing coordinate data from spreadsheets, PDFs, and legacy systems. Step-by-step cleaning strategies for every major format.

Learn how to import coordinates into AutoCAD from CSV, spreadsheets, and survey data. Compare manual entry, scripts, and DXF, and avoid placement errors.

Step-by-step guide to importing CSV coordinates as points in QGIS and ArcGIS Pro: choosing X/Y fields, setting the right CRS, and fixing null island errors.

Troubleshoot coordinates that plot in the wrong location. Covers reversed lat/long, wrong coordinate systems, datum mismatches, and format confusion.

Fix coordinates that fail to appear on the map. Covers invalid formats, out-of-range values, extra text, wrong order, and parsing failures.

Diagnose why coordinates land close but not exactly right. Covers datum mismatches (WGS84 vs OSGB36), projection errors, and GPS accuracy limits.

Fix incomplete or malformed British National Grid references. Covers missing grid letters, unbalanced digits, and confusion with Easting/Northing.

Practical steps to clean and repair coordinates that fail to parse. Fixes for missing separators, wrong symbols, extra text, and format mismatches.

Understand why UTM and lat/long look completely different for the same location, how zones affect conversion, and when a mismatch signals a real error.

Compare the metric zone-based UTM grid with global lat/long coordinates. Learn why the numbers differ and when each is best for GIS, GPS, and mapping.

Compare the global UTM zone system with British National Grid. Learn their different projections, coverage areas, and when each is best for GIS work.

Understand how UTM zones relate to raw Easting/Northing values, why both use metres but are not interchangeable, and when to use each.

Compare metre-based grid coordinates with global angular lat/long. Learn why the numbers differ and when each is best for surveying, GIS, and mapping.

Compare British National Grid references with global lat/long coordinates. Learn why they look different and when each is better for UK mapping.

Understand the difference between alphanumeric UK Grid references and raw Easting/Northing metre values, and when to use each in British mapping.

Compare Degrees Minutes Seconds with Decimal Degrees. Learn why both exist and which is better for navigation, GPS devices, web maps, and spreadsheets.

Compare Degrees Minutes Seconds with Degrees Decimal Minutes. Learn how they differ and which is better for aviation, marine GPS, and navigation.

Compare Degrees Decimal Minutes with Decimal Degrees. Learn why both exist and which is better for marine GPS, web maps, geocaching, and databases.

Compare MGRS and UTM coordinate systems. Learn how MGRS encodes UTM into a compact grid reference and when to use each.

State Plane vs UTM compared. Coverage, zone size, accuracy, units, datum, and distortion explained, with a clear answer to which system to use and when.

Convert UTM coordinates into latitude and longitude quickly and check the result on the map.

Convert latitude and longitude into UTM coordinates for GIS, mapping, and fieldwork.

Convert UK Grid references into latitude and longitude for GPS and web map use.

Convert latitude and longitude into UK Grid references for Great Britain mapping.

Convert Easting and Northing values into latitude and longitude for easier plotting and sharing.

Convert latitude and longitude into Easting and Northing values for project and survey workflows.

Convert DMS coordinates into Decimal Degrees quickly and plot them on the map.

Convert Decimal Degrees into DMS format for navigation, maps, and reports.

Convert Degrees Decimal Minutes into Decimal Degrees for GPS and web map use.

Convert Decimal Degrees into Degrees Decimal Minutes for GPS and navigation workflows.

Convert UTM coordinates into UK Grid references for Great Britain mapping tasks.

Convert UK Grid references into UTM coordinates for GIS and field data workflows.

Convert MGRS coordinates to latitude and longitude instantly for Google Maps, GPS devices, and web mapping.

Convert State Plane coordinates to latitude and longitude. Works with every NAD83 zone, US Survey Feet, metres, and international feet, with FIPS lookup.