DMS to decimal coordinates converter
Convert latitude and longitude between degrees, minutes, seconds and decimal degrees in a CSV or TSV, preserving every original row and column.
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DMS to decimal coordinates converter
Preparing points for a map, GIS import or field report often means changing coordinate notation in a spreadsheet. This converter accepts separate latitude and longitude columns with decimal degrees or degrees, minutes and seconds. It appends both formats for every row while keeping IDs and other source columns intact. A value such as 34°12'30"N becomes 34.20833333; a western longitude becomes negative in decimal degrees. The row-numbered error stops a malformed batch so one bad position cannot pass unnoticed. Check the source datum before using the points: changing notation does not convert UTM, State Plane or any other projected coordinate system.
How to use this tool
- Export locations as UTF-8 CSV or TSV with separate latitude and longitude columns. Upload or drag the file in, import a direct public URL, or try the sample coordinates.
- Select the column separator and enter the exact latitude and longitude headers. Decimal degrees and DMS values can be mixed; invalid rows show their CSV row number.
- Check the converted decimal and DMS columns in the preview, then download the CSV with the original columns preserved.
Supported input formats
CSVTSVTXT
Available settings
- Column separator
- Latitude column header
- Longitude column header
Output and limitations
Convert latitude and longitude between degrees, minutes, seconds and decimal degrees in a CSV or TSV, preserving every original row and column.
Upload or drag in one UTF-8 CSV or TSV up to 5 MB, import a direct public file URL, or paste up to 12,000 characters after the or separator. Set the column separator and exact latitude and longitude header names. Values may use decimal degrees, DMS such as 34°12'30"N, or a mixture in the same file; one compass letter may appear at the start or end. The output keeps all original columns and appends decimal latitude/longitude to up to eight decimal places and DMS latitude/longitude to 0.001 second. Invalid or blank values stop conversion with the CSV row number; no coordinate is guessed. The tool converts notation only. It does not reproject UTM, State Plane or another coordinate reference system, and does not determine the datum. Use geographic latitude/longitude in the datum your map requires. Limits: 10,000 rows, 100 columns and 20 MB output. Spreadsheet formula-like source cells are escaped in the CSV export.
Can I mix decimal and DMS values in one file?
Yes. Each latitude and longitude cell is parsed independently. Use a compass letter or a leading minus sign, not both. The report stops at the first invalid row instead of silently changing its position.
Does this convert UTM or other projected coordinates to latitude and longitude?
No. It changes how geographic latitude and longitude are written. It cannot identify or transform a map projection or datum. First use a GIS tool with the correct coordinate reference system when the source uses eastings and northings.
What if processing fails?
Check the supported formats and file limits, then try a smaller file. Keep an original copy. A clear error message will explain an unsupported input or an unavailable processing service.