MGA2020 converter
Convert GDA2020 latitude and longitude to MGA2020 easting and northing in zones 49–56. Includes batch conversion, convergence and point scale.
This tool runs in your browser and nothing you enter is uploaded. Check results independently before relying on them for survey work.
How it works
The Karney (2011) Krueger n-series through order n⁶ projects GDA2020 on GRS80 (a = 6378137 m; 1/f = 298.257222101). MGA uses k₀ = 0.9996, false easting 500000 m, false northing 10000000 m and central meridian 6 × zone − 183 degrees. The inverse recovers latitude by iteration. Convergence and point scale come from the projection derivatives. This is a projection, not a datum transformation. Southern latitudes −80° to 0° and longitudes within 9° of the selected central meridian are supported.
Worked example
For GDA2020 latitude −27.4478° and longitude 153.1667°, auto zone is 56. MGA2020 gives E 516473.169 m, N 6963954.160 m, grid convergence +0°04′36.62″ and point scale 0.99960335. Load example to calculate this point.
Sources and further reading
Geoscience Australia’s Map Grid of Australia 2020 page defines MGA2020: the GRS80 ellipsoid, a central scale factor of 0.9996, a false easting of 500000 m and a false northing of 10000000 m. Section 4.1.1 of the ICSM GDA2020 Technical Manual (version 1.8) recommends the Krueger n-series equations (Karney, 2011) for converting between geographic and grid coordinates when work spans more than one zone.
Frequently asked questions
Does this convert GDA94 to GDA2020?
No. Both geographic and grid coordinates must use GDA2020. Changing the projection does not change the datum.
Which MGA2020 zones cover Queensland?
Zones 54, 55 and 56. Brisbane, the Gold Coast, the Sunshine Coast and Toowoomba are in zone 56, Townsville and Cairns are in zone 55, and Mount Isa is in zone 54. Auto mode picks the zone from the longitude.
How is the automatic zone chosen?
Each zone spans six degrees of longitude. Boundaries go to the eastern zone: 114° selects 50 and 150° selects 56. Auto mode covers 108° up to, but not including, 156°. You can choose zones 49–56 manually.
What do convergence and point scale mean?
Grid convergence is the angle you add to a true azimuth to get a grid bearing: grid bearing = azimuth + grid convergence, as in the GDA2020 Technical Manual. In the southern hemisphere it is positive east of the central meridian and negative west of it. Point scale is grid distance divided by ellipsoidal distance locally; it is not a ground-to-grid combined scale factor.
Can I convert several points at once?
Yes. Paste comma-separated rows in the batch box. Each inverse row includes its own zone. The table and Copy CSV include coordinates, zone, convergence and scale.
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