MGA94 to MGA2020 Coordinate Converter
A free, browser-based converter. Runs entirely in your browser — no sign up, nothing stored.
Input (MGA94)
Optional, for distortion-corrected accuracy. The GDA94⇄GDA2020 conformal+distortion grid comes from ICSM; it is read locally in your browser and never uploaded.
Which method is more accurate?
7-parameter conformal — reproduces the official conformal transformation to the millimetre, but does not model local GDA94 network distortion, so it can differ from state survey control by up to about 0.3 m (typically under 0.1 m). Best for GNSS / CORS / AUSPOS-derived data.
NTv2 conformal + distortion — also corrects that local distortion, matching official state cadastral / survey control to roughly 0.01–0.05 m. The most accurate option; recommended for data tied to local survey marks (e.g. SCIMS).
Coordinates are transformed in your browser and never uploaded.
Result (MGA2020)
Enter a coordinate and press Convert to see the result.
How to use this calculator
- Choose the direction — MGA94 → MGA2020 or MGA2020 → MGA94 (use Swap to flip it).
- Pick the MGA zone, then enter the easting and northing in metres (optionally a point ID and ellipsoidal height).
- Press Convert to read the new coordinate, the shift (ΔE/ΔN, distance and bearing) and method/EPSG details. Paste or upload a CSV in the batch panel to convert many points at once.
How it works
MGA94 and MGA2020 are the same Map Grid of Australia projection on different datums (GDA94 vs GDA2020), so the shift is not a fixed easting/northing offset. The tool converts the grid coordinate to geographic, applies the official GDA94↔GDA2020 7-parameter conformal (coordinate-frame rotation) transformation in 3D Cartesian space, then projects back to the grid.
It uses the standard 7-parameter method by default (ICSM GDA2020 Technical Manual); the reverse direction negates the seven parameters. For distortion-corrected results you can optionally load the official ICSM conformal + distortion NTv2 grid (.gsb) via the Method picker — the ~79 MB grid is read locally in your browser (never uploaded) and is used wherever it covers your point, falling back to the 7-parameter transform outside coverage.
Worked example
Australia's ~1.8 m shift. Across Australia, GDA94 coordinates move roughly 1.8 m to the north-east in GDA2020 — so MGA94 and MGA2020 eastings/northings for the same point differ by about that much, varying with location.
Tips
- Zones 49–56 cover mainland Australia; the central meridian of a zone is zone × 6 − 183 degrees.
- This tool is for planning, checking, GIS and survey support. For legal/cadastral or certified work, verify with official services or professional survey software. Not affiliated with Geoscience Australia or ICSM.
Frequently asked questions
Is MGA94 the same as GDA94?
MGA94 is the projected grid (eastings/northings) based on the GDA94 datum. MGA2020 is the same grid based on GDA2020.
Can I use a simple offset?
No. The shift varies by location and method, so a single fixed offset is wrong. A proper converter goes grid → geographic → datum transformation → grid, which is what this tool does.
Which method should I use?
The standard 7-parameter conformal method suits GNSS/CORS-derived and general GIS/planning/mining data. Data tied to local survey control where distortion matters should use the conformal + distortion NTv2 grid — load the official ICSM .gsb file via the Method picker.
How do I use the NTv2 distortion grid?
Download the official GDA94⇄GDA2020 conformal+distortion grid (.gsb, ~79 MB) once from ICSM (github.com/icsm-au/transformation_grids), then choose 'Load official ICSM grid' under Method. It is read in your browser only — never uploaded — and applied automatically where it covers your point.
Does this convert heights?
No AHD height conversion. Height is only used (optionally) for the horizontal 7-parameter transformation; it is not converted to a vertical datum.
Do my coordinates upload to Zerdly?
No. Single-point and batch CSV conversions run entirely in your browser — nothing is uploaded, stored or logged.
How accurate is it?
The projection and 7-parameter maths are millimetre-level and match official calculators using the same method. That is calculator agreement, not a certified real-world accuracy guarantee — verify before cadastral, certified control, engineering set-out or safety-critical work.
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Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.