What Is GDA2020?

by Christopher O'Keeffe June 04, 2026

Understanding Australia’s modern mapping datum — and why it matters when using NSW Topographic Maps, QTopo maps and AUSTopo maps.

If you have purchased a modern Australian topographic map, you may have noticed a technical term printed in the map margin or product description:

GDA2020

For many map users, it looks like just another piece of mapping jargon.

But GDA2020 is important.

It is part of the invisible reference framework that allows maps, GPS devices, survey data, grid references, coordinates and digital mapping systems to line up correctly across Australia.

Whether you are using a NSW Topographic Map, a Queensland QTopo map, or one of the new AUSTopo 1:250,000 maps, understanding GDA2020 helps explain how modern Australian mapping works — and why newer maps are better aligned with today’s satellite positioning systems.

At Mapworld, many of our current topographic products reference GDA2020, MGA2020, UTM, AHD and modern coordinate systems. This guide explains what those terms mean in plain English, why Australia moved from GDA94 to GDA2020, and what map users need to know in the field.

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What Does GDA2020 Mean?

GDA2020 stands for:

Geocentric Datum of Australia 2020

A datum is a reference framework used to define positions on the Earth.

In simple terms, it is the mathematical foundation that tells a map where everything should sit.

Without a datum, coordinates would not mean much. A latitude and longitude, grid reference or GPS point only becomes useful when everyone agrees on the reference system behind it.

GDA2020 is Australia’s modern national datum. It replaced the older GDA94 datum and provides a more accurate reference framework for modern mapping, surveying, GPS and geospatial data.

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Why Did Australia Need a New Datum?

Australia is not fixed in place.

It sits on the Australian tectonic plate, which slowly moves over time.

That movement may seem small from day to day, but over decades it becomes significant for precise mapping and positioning.

The older GDA94 datum was based on Australia’s position in the 1990s. Since then, satellite positioning, GPS, surveying technology and geospatial systems have become far more accurate.

As technology improved, the difference between older map coordinates and modern satellite positioning became more noticeable.

GDA2020 was introduced to better align Australia’s national mapping framework with modern GNSS and GPS technology.

For everyday bushwalking, the difference may often be small.

For surveyors, engineers, emergency services, GIS professionals, land managers and precision fieldwork, it matters greatly.

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GDA2020 vs GDA94: What Changed?

The simplest explanation is this:

GDA2020 places Australian coordinates closer to where modern GPS systems say they should be.

GDA94 was very good for its time.

But Australia has moved since 1994.

GDA2020 updates the reference framework so modern maps and positioning systems line up more accurately.

The difference between GDA94 and GDA2020 is often around 1.5 to 1.8 metres, depending on location and dataset.

For a walker using a printed 1:25,000 topographic map, that difference may be hard to see on paper.

For a surveyor, engineer or GIS user working with high-accuracy equipment, it is very important.

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Why GDA2020 Matters for Map Users

For most recreational users, GDA2020 is not something to fear.

You do not need to become a surveyor to use a map.

But you should understand what it means, especially when working with coordinates.

GDA2020 matters when you are:

• Entering grid references into a GPS

• Comparing paper maps with digital maps

• Using coordinates from different sources

• Working with GIS data

• Conducting fieldwork

• Using survey-grade positioning

• Sharing coordinates with others

• Matching map features to satellite imagery

• Using newer topographic map series

The key point is consistency.

If your map, GPS, phone app and coordinate data are all using the same datum, everything should align more cleanly.

If they are using different datums, small positional differences may appear.

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GDA2020 and MGA2020: What Is the Difference?

You may also see the term MGA2020.

This stands for:

Map Grid of Australia 2020

GDA2020 is the datum.

MGA2020 is the grid system based on that datum.

Think of it this way:

• GDA2020 defines the position of Australia on the Earth.

• MGA2020 provides the grid coordinates used on many maps.

MGA2020 is based on the Universal Transverse Mercator system, commonly known as UTM.

On many modern Australian topographic maps, grid references are based on MGA2020.

This allows users to work with easting and northing coordinates rather than latitude and longitude.

For practical navigation, MGA grid references are often easier to use with a map and compass.

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GDA2020 and AHD: What About Height?

Another term you may see on Mapworld topographic map products is AHD.

AHD stands for:

Australian Height Datum

While GDA2020 is concerned with horizontal position — where something is on the Earth — AHD relates to height or elevation.

On topographic maps, elevation is shown through:

• Contour lines

• Spot heights

• Benchmarks

• Trig points

• Relief features

So when you see references such as GDA2020, AHD, it means the map is using modern Australian horizontal positioning along with Australia’s height reference system.

This is especially important for topographic maps because they do not merely show where features are.

They also show how high or low the land is.

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GDA2020 and NSW Topographic Maps

New South Wales topographic maps are among the most heavily used topo maps in Australia.

They are popular with:

• Bushwalkers

• Outdoor educators

• Surveyors

• Emergency services

• Land managers

• Environmental consultants

• Four-wheel-drivers

• Field professionals

Mapworld’s NSW topographic map range includes detailed 1:25,000 and 1:50,000 mapping options for many of the state’s most important outdoor regions.

NSW Spatial Services moved its newer topographic mapping to GDA2020, replacing the older GDA94 datum used in previous GeoPDF mapping.

This means modern NSW topographic maps are better aligned with current GPS and GNSS positioning systems.

For everyday navigation, the printed map still works in the familiar way.

You can still read contours, identify creeks, follow tracks, locate ridges and work with grid references.

But behind the map, the coordinate framework is more modern.

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NSW 1:25,000 Topographic Maps

For detailed bushwalking and field navigation, NSW 1:25,000 topographic maps remain one of the best choices.

At this scale:

1 cm on the map represents 250 metres on the ground.

This level of detail is ideal for:

• Bushwalking

• Off-track navigation

• National parks

• Wilderness areas

• Search and rescue

• Survey work

• Environmental assessment

• Outdoor education

When combined with GDA2020-based coordinate information, modern NSW topographic maps offer a strong link between traditional paper navigation and GPS-supported fieldwork.

A bushwalker may not think about the datum every time they unfold the map.

But when coordinates matter, the datum becomes part of the confidence behind the map.

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NSW 1:50,000 Topographic Maps

Mapworld’s NSW 1:50,000 topographic maps provide a useful balance between detail and coverage.

At this scale:

1 cm on the map represents 500 metres on the ground.

These maps are excellent for:

• Regional navigation

• Four-wheel-driving

• Field operations

• Land management

• Emergency planning

• Broader route planning

A 1:50,000 NSW topographic map covers more ground than a 1:25,000 sheet while still showing important terrain and access information.

For many users, this scale is the practical middle ground.

With modern GDA2020 alignment, these maps remain useful for both traditional map reading and coordinate-based planning.

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GDA2020 and Queensland QTopo Maps

Queensland’s QTopo mapping system is one of the most useful topographic mapping resources in Australia.

QTopo maps cover Queensland’s vast and varied landscape, including:

• Rainforest ranges

• Coastal plains

• National parks

• Cape York

• Gulf Country

• Channel Country

• Agricultural regions

• Mining districts

• Remote inland areas

• Urban fringe areas

Mapworld’s QTopo collection includes maps at scales such as:

• 1:10,000

• 1:25,000

• 1:50,000

• 1:100,000

These maps are used by recreational and professional customers alike.

Queensland’s adoption of GDA2020 helps bring state mapping into line with modern positioning systems, allowing smartphones, GPS receivers and other positioning technologies to align more accurately with mapped features.

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QTopo 1:10,000 Maps

QTopo 1:10,000 maps are highly detailed.

At this scale:

1 cm on the map represents 100 metres on the ground.

These maps are ideal for:

• Surveying

• Engineering

• Environmental consulting

• Emergency operations

• Detailed land management

• Property and infrastructure work

• High-resolution field planning

Because the scale is so detailed, positional accuracy becomes more important.

This is where GDA2020 matters more visibly.

For professionals using GPS, GIS or survey data alongside a printed QTopo 1:10,000 map, consistent datum information helps reduce confusion and improves alignment between map and field data.

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QTopo 1:25,000 Maps

QTopo 1:25,000 maps are excellent for detailed outdoor navigation and field use.

They are particularly useful in places such as:

• Lamington National Park

• Mount Barney

• Girraween

• Carnarvon Gorge

• Glass House Mountains

• Wet Tropics

• Scenic Rim

• Cape York

• Queensland state forests

For bushwalkers, these maps show the terrain clearly.

For professionals, they provide detailed spatial context.

When paired with GDA2020-based coordinates, they work well with modern GPS devices and field applications.

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QTopo 1:50,000 and 1:100,000 Maps

QTopo 1:50,000 and 1:100,000 maps are excellent for broader regional planning.

They are commonly used for:

• Four-wheel-driving

• land management

• emergency planning

• environmental assessment

• regional fieldwork

• rural access planning

• property-scale overview

• outback travel

At these scales, the difference between older and newer datums may be less noticeable on paper, but it still matters when using coordinates digitally.

The practical lesson is simple:

Make sure your GPS, mapping app and coordinate data are using the same datum as your map.

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GDA2020 and AUSTopo Maps

The AUSTopo 1:250,000 Australian Digital Topographic Map Series is one of the most important modern national topographic map series.

At Mapworld, AUSTopo maps are available as printed topographic maps, providing broad regional coverage for Australia.

The AUSTopo series is especially useful because it provides a consistent national mapping framework at 1:250,000 scale.

At this scale:

1 cm on the map represents 2.5 kilometres on the ground.

This makes AUSTopo maps ideal for:

• Regional planning

• Outback travel

• Emergency management

• Environmental planning

• Land management

• Logistics

• Broad route planning

• Professional field operations

• Remote-area navigation

Mapworld’s AUSTopo product descriptions note that the series uses:

• Geographical and MGA coordinates

• GDA2020 datum

• AHD height reference

• Universal Transverse Mercator projection

This makes the AUSTopo series a modern and nationally consistent topographic mapping product.

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Why AUSTopo Uses GDA2020

AUSTopo is a modern mapping series.

It makes sense that it uses Australia’s current datum.

Because it covers the whole country at a consistent scale, GDA2020 helps ensure that national topographic mapping aligns properly with contemporary coordinate systems.

This is important for users who work across state borders.

A land manager, emergency planner, geologist, remote-area traveller or government agency may use AUSTopo maps across multiple jurisdictions.

A modern national datum helps create consistency.

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AUSTopo for Outback and Remote-Area Users

For outback users, AUSTopo maps provide big-picture regional context.

They are particularly useful in places where distances are vast and decisions depend on understanding the broader landscape.

AUSTopo maps are well suited to:

• Desert travel

• Remote station country

• Long-distance route planning

• Regional infrastructure planning

• National parks and reserves

• Mining and exploration areas

• Emergency response planning

• Environmental fieldwork

In these contexts, GPS and paper maps often work together.

GDA2020 helps keep the relationship between digital coordinates and printed map information more consistent.

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Does GDA2020 Matter for Bushwalkers?

Yes — but in a practical, not frightening, way.

If you are walking on marked trails with a paper map and compass, you may not consciously use GDA2020 at all.

You will still read:

• Tracks

• creeks

• contours

• ridges

• saddles

• cliffs

• roads

• grid lines

• place names

as you always would.

But if you are using a GPS, phone app or emergency coordinates, the datum becomes more important.

For example:

• If you record a waypoint on your GPS, what datum is it using?

• If a map gives a grid reference, does your device match it?

• If you share coordinates with another person, are you both using the same system?

• If you compare older GDA94 information with newer GDA2020 mapping, do you understand there may be a small offset?

For recreational users, the key is awareness.

For professionals, the key is precision.

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Does GDA2020 Matter for Surveyors and Field Professionals?

Absolutely.

For surveyors, engineers, GIS officers, environmental consultants, emergency services, infrastructure planners and land managers, GDA2020 is highly relevant.

These users often rely on:

• High-accuracy GNSS

• GIS datasets

• cadastral information

• survey control

• infrastructure data

• environmental layers

• field-collected coordinates

• aerial imagery

• drone data

• digital elevation models

In those contexts, a difference of 1.5 metres can matter.

Using the correct datum helps ensure all spatial information aligns correctly.

If a project combines older GDA94 data with newer GDA2020 data, proper transformation may be required.

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What Should Map Users Check?

Before using coordinates seriously, check:

1. The Map Datum

Look in the map margin or product description for GDA2020, GDA94 or another datum.

2. The Grid System

Check whether the map uses MGA2020, MGA94, latitude/longitude or another coordinate system.

3. Your GPS Settings

Many GPS units allow you to set the datum.

Make sure it matches your map or the coordinate source you are using.

4. The Age of the Map

Older maps may use older datums.

Historical maps should not be used for precise navigation.

5. The Coordinate Source

If someone gives you coordinates, ask what datum they are based on.

This is especially important in professional or emergency contexts.

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Common Terms Explained

Datum

The reference framework used to define positions on Earth.

Example: GDA2020.

GDA94

The previous Australian datum based on Australia’s position around 1994.

GDA2020

Australia’s modern national datum, better aligned with current satellite positioning systems.

MGA2020

Map Grid of Australia 2020 — the grid coordinate system based on GDA2020.

UTM

Universal Transverse Mercator — the projection system used for many grid-based maps.

AHD

Australian Height Datum — Australia’s height reference system used for elevation.

GNSS

Global Navigation Satellite System — a broad term that includes GPS and other satellite positioning systems.

GPS

Global Positioning System — the satellite navigation system many people use for outdoor navigation.

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Paper Maps and Modern Datums

It may seem strange that a paper map needs a modern datum.

After all, once printed, the map does not move.

But the datum still matters because the printed map is built from coordinate data.

Grid lines, latitude and longitude, feature positions and spatial datasets all depend on a reference framework.

A modern paper topographic map is not just artwork.

It is the printed expression of spatial data.

That is why NSW Topographic Maps, QTopo maps and AUSTopo maps all benefit from modern coordinate systems.

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GDA2020 and Custom Printing

Mapworld also supplies printed topographic maps in paper, laminated and waterproof formats.

For customers ordering NSW topo maps, QTopo maps or AUSTopo maps, the datum is part of the map’s technical foundation.

This matters for:

• fieldwork

• route planning

• emergency preparation

• professional reports

• map enlargements

• training materials

• wall displays

• custom laminated maps

If your work depends on accurate coordinates, always keep the datum information visible and understood.

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Why Buy GDA2020-Based Topographic Maps from Mapworld?

Mapworld stocks a large range of modern Australian topographic mapping, including:

• NSW 1:25,000 topographic maps

• NSW 1:50,000 topographic maps

• Queensland QTopo maps

• QTopo 1:10,000 maps

• QTopo 1:25,000 maps

• QTopo 1:50,000 maps

• QTopo 1:100,000 maps

• AUSTopo 1:250,000 maps

• Geoscience Australia mapping

• laminated, paper and waterproof options

• compasses and navigation tools

These maps serve everyone from weekend bushwalkers to professional field teams.

The important thing is choosing the right scale, format and datum-aware workflow for your use.

For many customers, the question is not simply “Which map do I need?”

It is:

Which map scale, format and coordinate framework best suits the job?

That is exactly where Mapworld can help.

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Final Thoughts

GDA2020 may sound technical, but its purpose is straightforward.

It helps modern Australian maps, coordinates and positioning systems line up more accurately.

For NSW Topographic Maps, QTopo maps and AUSTopo maps, GDA2020 is part of the shift toward more precise, nationally consistent and GPS-aligned mapping.

For most recreational users, it is something to be aware of.

For professional users, it is something to manage carefully.

Either way, understanding GDA2020 helps you use maps more intelligently.

Because a topographic map is more than contours, creeks, roads and tracks.

It is part of a national spatial system.

And GDA2020 is the framework helping that system point to the right place.

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Frequently Asked Questions

What is GDA2020?

GDA2020 stands for Geocentric Datum of Australia 2020. It is Australia’s modern national datum used to define coordinates and positions across the country.

Why did Australia move from GDA94 to GDA2020?

Australia moved to GDA2020 because the Australian tectonic plate has shifted since GDA94 was established, and modern GPS/GNSS positioning systems are far more accurate than older mapping systems.

What is the difference between GDA2020 and MGA2020?

GDA2020 is the datum. MGA2020 is the grid coordinate system based on that datum.

Does GDA2020 matter for bushwalking?

Yes, especially if you use GPS coordinates, grid references or digital mapping apps. For simple track walking, the difference may not be obvious, but it is still worth understanding.

Do NSW Topographic Maps use GDA2020?

Modern NSW topographic mapping uses GDA2020, replacing the earlier GDA94 framework used in previous GeoPDF mapping.

Do QTopo maps use GDA2020?

Queensland mapping has moved from GDA94 to GDA2020 to better align state mapping with modern satellite positioning systems.

Do AUSTopo maps use GDA2020?

Yes. Mapworld’s AUSTopo 1:250,000 map products reference GDA2020, AHD and UTM projection information.

What is AHD?

AHD stands for Australian Height Datum. It is Australia’s height reference system and is used for elevation information such as contours and spot heights.

Can I use old GDA94 coordinates on a GDA2020 map?

You may see a small positional difference. For recreational use this may be minor, but for professional work, coordinates should be properly transformed.

Should my GPS be set to GDA2020?

If you are using a GDA2020 map or GDA2020 coordinates, your GPS or mapping app should be set accordingly where possible.

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