Field guide
Convert coordinates with an explicit reference
Start with source documentation, then review each field, coordinate meaning and deliverable.
Prepare a batch with a documented coordinate reference
A batch coordinate converter is useful when a complete point file needs a different coordinate representation for GIS, mapping or a receiving project. The important starting point is a known source reference. A pair of large numbers does not reveal its datum, projection, zone, hemisphere, unit or local origin. Obtain the export settings, project specification or coordinate reference identifier from the data supplier before choosing settings here.
Keep an untouched copy of the received file. Record its revision, the purpose of this conversion and the height meaning in the reference field. This note travels with the calculation report and with a subsequent local tool handoff. It is a project note, not a replacement for a formal coordinate reference definition. If the source description is contradictory, resolve that contradiction before treating a plausible result as correct.
Read CSV, text or an Excel worksheet
Choose a UTF-8 comma, semicolon or tab separated file, paste a small table, or load an XLSX workbook. For a workbook, explicitly select the sheet that contains the point table. The selected worksheet becomes a text table for the same field validation used by CSV. Formulas, dates and error cells are rejected with their cell address; paste verified values in the source workbook before trying again.
Map longitude or Easting to the first coordinate role and latitude or Northing to the second. Column numbers start at one; use zero only for optional names, heights or descriptions. Names such as 0007 remain text, and an absent height stays absent. Additional columns are retained in the full JSON source record, while the standard output point table contains the five displayed point fields. Check those field choices before approving the export.
Choose the source and target from supported definitions
The first release supports WGS84 longitude and latitude with northern or southern UTM, and CGCS2000 longitude and latitude with standard three-degree or six-degree Gauss–Krüger coordinates. Both ends must use the same datum. Projection coordinates are in metres and geographic coordinates are decimal degrees. The displayed definition identifies the selected EPSG reference, including the coordinate order used by this interface.
This is a deliberately explicit list, not an arbitrary EPSG lookup service. A project using a custom central meridian, a different false origin, a national grid not listed here or a time-dependent reference needs another verified operation. Do not select a nearby standard zone to approximate a custom project definition. The conversion report records both projection definitions so a receiving person can reproduce the actual operation rather than relying on a page title.
Set the UTM zone and hemisphere separately
A UTM zone number selects a longitudinal strip. Hemisphere is a separate choice and affects the northing convention. Enter the zone stated in your source documentation for inverse conversion, and the required zone for the output. The implementation checks recovered longitude and latitude against the selected standard zone and supported latitude range. It reports an error instead of quietly reassigning a point to another zone.
The supported latitude interval is 80 degrees south through 84 degrees north, with the appropriate hemisphere selected. This version uses ordinary six-degree zone boundaries and does not implement the widened Norway or Svalbard zone cases. Files crossing an ordinary boundary may need to be divided by an explicitly approved zone policy. A range check helps detect mistakes, but does not identify an unknown reference or prove that a coordinate belongs to the intended site.
Distinguish Gauss–Krüger zone widths and easting prefixes
For CGCS2000, choose either three-degree zones 25 through 45 or six-degree zones 13 through 23. The interface displays the resulting central meridian. For example, three-degree zone 39 and six-degree zone 20 both use 117 degrees east as the central meridian, but the band definitions and zone prefixes differ. A central meridian alone does not describe every aspect of the source convention.
The prefix checkbox states whether Easting contains the million-metre zone prefix in addition to the usual false easting. It applies separately to source and target. A value near 39,500,000 is therefore interpreted differently from one near 500,000. Do not remove a leading number in a spreadsheet until the file convention has been established. Incorrect prefixes commonly produce out-of-zone results, which remain visible as failed rows in the report.
CGCS2000 points are also checked against the selected EPSG area-of-use bounding box. The displayed west, south, east and north limits are necessary bounds, not a detailed national boundary or an accuracy certificate. A point outside them is reported as an error.
Understand what changes and what stays as supplied
Only the horizontal coordinate representation changes. Height text is retained without a geoid correction, vertical datum change or unit conversion. A height of 12.300 remains that text in the point output; the retained decimals are not a new claim of precision. Name and description values are carried into the output, while all original columns remain in JSON for a complete audit.
WGS84 and CGCS2000 are not silently treated as the same datum. Choosing one at the source and the other at the target is blocked. This tool also does not remove GCJ-02 or BD-09 offsets, infer an unknown site grid, or estimate a local rotation and translation from control points. For the latter task, use the separate control-point fitting tool and keep its residuals and project assumptions with the result.
Review failures before accepting a point table
Conversion runs locally in a worker and can be cancelled. The preview retains the source line, point name, original coordinates, result coordinates, original height and error text. A malformed coordinate or out-of-zone record blocks the complete point export. Valid rows can still be inspected, but the application does not silently deliver a shortened file with the bad records omitted.
Use the page controls to inspect the batch and download the JSON report when a correction is needed. The report includes every input row, the original source text, selected definitions and individual failures. Correct the source or settings, then run again. Any edit invalidates the previous result and its approval. This prevents a download from accidentally mixing an old calculation with a newly selected coordinate reference.
Check a known point and make a useful handoff
The worked example uses longitude 12 and latitude 56 in WGS84 with UTM zone 32 north. The expected projected position is approximately Easting 687071.44 and Northing 6210141.33 metres. This example is useful for checking field order and hemisphere. For a real project, also compare an independently known control position in the relevant area; a successful example does not establish your source file's reference.
After review, download CSV or XLSX together with the report. XLSX cells are written as text to preserve identifiers and decimal strings; explicitly convert the relevant columns to numbers if your next spreadsheet calculation requires that. WGS84 geographic output can continue to the KML tool, and projected output can continue to the point checker. Browser-to-browser handoff stays in session memory and requires the source tab to remain open. No point coordinates are placed in the handoff URL.
Work within the supported limits
Each input is limited to ten mebibytes and one hundred thousand point records. XLSX input also has worksheet cell and decompressed archive limits. Oversized or unsupported workbooks need to be simplified or split while preserving their references and row identifiers. Blank source lines are counted separately; they do not become invented survey points.
Save the complete report with the original delivery rather than retaining only a screenshot or rounded preview. Computed decimal digits describe the numerical result, not survey accuracy. The output still depends on the correctness of the source reference, measured coordinates and receiving project's requirements. Review a meaningful independent check before using a converted file for consequential layout or engineering decisions.