Coordinate reference systems trip up more GIS beginners than almost anything else. Data in the wrong projection doesn't always look "wrong" at first glance — it just quietly produces incorrect areas, distances, or a map that doesn't line up with everything else you're working with. CRS Converter handles detection and reprojection in one place, searching the real, complete EPSG registry rather than a short preset list.
What you need before you start
Any spatial file — GeoJSON, Shapefile (zipped), GeoPackage, KML/KMZ, or a spreadsheet with coordinates or WKT. You don't need to already know its current coordinate system; the tool detects it from the file itself where possible.
The steps
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Upload your file
Drag it onto CRS Converter. If your file carries its own CRS information (like a Shapefile's .prj), it's detected and shown immediately — no guessing what coordinate system you're starting from.
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Search for your target CRS
Type a name ("UTM zone 43N", "British National Grid", "State Plane California") or an EPSG code directly if you already know it. The search covers the real EPSG registry — over 7,000 entries — not a short list of common presets.
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Reproject and export
Run the conversion and export the result in the same range of formats you can upload — GeoJSON, Shapefile, GeoPackage, KML, or CSV.
Why this matters for area and distance
Geographic coordinates (plain latitude/longitude) aren't a metric system — a degree of longitude covers a different real distance depending on how far you are from the equator. Any area or distance calculation done directly on unprojected data is distorted by exactly that amount. Reprojecting to an appropriate local projection (typically UTM) before measuring anything is standard practice, not an optional step.
Working with data in the wrong projection?
Open CRS Converter →Frequently asked questions
What UTM zone should I use? The one that covers your data's real-world location — CRS Converter suggests one automatically based on the coordinates in your file, a sensible default for most metric area and distance work. If your data spans more than one UTM zone, a state- or country-level projection is usually a better fit than forcing a single UTM zone.
Can I reproject without knowing the current CRS? Yes — most Shapefiles carry this in their .prj file, and it's detected and shown automatically on upload.