Projection comparator

Compare map projections side by side

Pick two map projections and see them side by side: what each one keeps, what it distorts, how big Greenland looks on it and what it is good for.

Click a card to choose another projection.

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Popular comparisons

The full comparison with explanations: Mercator vs Equal Earth →

Mercator and Equal Earth: features compared
Feature	Mercator	Equal Earth
Basics
Distortion class	Conformal	Equal-area
Graticule type	Cylindrical	Pseudocylindrical
Creator	Gerardus Mercator	B. Šavrič, T. Patterson, B. Jenny
Year	1569	2018
What it looks like	Meridians and parallels form a rectangular grid, and the spacing between parallels grows toward the poles, so polar regions are hugely enlarged.	Parallels are straight lines, the poles are flat lines, and the sides of the map are gently rounded, much like Robinson.
Distortion
Area	Distorted	Preserved
Shape	Preserved	Distorted
Distances	Distorted	Distorted
Angles and directions	Preserved	Distorted
Continuity	Preserved	Preserved
By the numbers
Greenland on the map, as a share of Africa	105%15× too large	7.1%True proportion
Average angular distortion over land	0°None, the map is conformal	32°
Practical traits
Map outline	Rectangle	Rectangle with rounded sides
Rhumb lines (constant bearing) drawn straight	Yes	No
Great circles (shortest routes) drawn straight	No	No
A pole at the centre of the map	No	No
Where the map is cut	Nowhere, the map is continuous	Nowhere, the map is continuous
All oceans in one piece	No	No
Use
Typical uses	Marine navigation, aviation, and most modern web mapping applications (Web Mercator, used by Google Maps, OpenStreetMap). Unsuitable for general educational wall maps due to extreme scale distortion.	Scientific publications, school textbooks, and global thematic maps that need to represent datasets relative to actual land area.
First choice for	Navigation and compass courses Web maps and apps	Comparing country sizes Thematic and data maps Teaching geography
A good alternative for	None of the jobs we describe	Wall maps and posters
Not recommended for	Comparing country sizes Thematic and data maps Wall maps and posters Flight routes Distances from one place The Arctic and Antarctica Teaching geography	Navigation and compass courses

The “By the numbers” rows are measured when the site is built, on the same maps the lab draws, over a grid of points every half degree (every 2° for all land). The true areas of Greenland and Africa come from our country and continent profiles.

Ready-made comparisons

The most compared pairs

Each of these pairs has its own page that explains the differences, gives the historical context and answers common questions.

How to read a projection comparison

Every flat world map distorts something. Setting two projections side by side shows what one keeps at the other's expense and what kind of map each one suits.

Five groups of features

Basics: the distortion class, graticule type, creator, year and a short description of how the map looks.
Distortion: whether the map keeps area, shape, distances, angles and continuity. These are the same ratings the projection guides show.
By the numbers: two values measured on the maps themselves, explained below.
Practical traits: the outline, straight rhumb lines and great circles, a pole at the centre and where the map is cut.
Use: typical uses and the jobs for which the projection finder recommends the map or advises against it.

Where the numbers come from

Greenland covers 2,166,086 km² and Africa 30.4 million km², so in reality Greenland is 7.1% of Africa's area. On every map we measure how much it enlarges Greenland on average and how much it enlarges Africa. An equal-area projection enlarges both equally, so it shows the true share.

The average angular distortion tells you by how many degrees a map skews angles at a typical place on land. We compute it from Tissot's indicatrices on a grid of points every 2° and average it weighted by true area. On a conformal map it is 0°, and the higher the value, the more shapes are stretched.

The results for Globe (Orthographic), Gnomonic and Azimuthal Equidistant depend on the chosen centre or on the visible part of the globe, so the table says so instead of giving a number.

How to share a comparison

Every choice is saved in the page address, so the link opens exactly the same pair. The most compared pairs have their own pages that explain the differences, and they open at those addresses. Copy the address from the browser bar or share the comparison with the Facebook and X buttons above the table. Your browser's Back button undoes the last change.

Frequently asked questions

What is the difference between a conformal and an equal-area projection?

A conformal projection keeps angles and shapes at a small scale, an equal-area one keeps area proportions. For example, Mercator is a conformal projection and Equal Earth is an equal-area projection. Greenland's share of Africa's area on the map: Mercator 105%, Equal Earth 7.1%, in reality 7.1%. Average angular distortion over land: Mercator 0°, Equal Earth 32°.

Which projections show the true sizes of countries?

Equal-area ones, which in our catalogue are Gall-Peters, Mollweide, Equal Earth, Werner Projection and Interrupted Goode Homolosine. On each of them Greenland covers 7.1% of Africa's area, the same as on the globe.

On which projection does Greenland look biggest?

Of the maps where it can be measured, the Mercator projection enlarges it most. Greenland covers 105% of Africa's area there, so it looks about 15 times larger than it really is.

How do I send someone my comparison?

Copy the page address from the browser bar or use the Facebook and X buttons above the table. The chosen pair is saved in the address, so the other person sees the same two projections.

How do you know what a projection is good for?

The rows in the Use section come from the same rules as the “Which map projection should I use?” finder. Each job links to a page with the full reasoning, alternatives and common mistakes.

ComparisonGreenland vs AfricaAfrica is about 14 times larger, though they look alike on Mercator.FinderWhich map projection should I use?Answer three questions about your map's purpose and see which projection fits.QuizName the projectionRecognise a projection from the shape of the world.ArticleWhy all maps of the world lieGauss's theorem and the mathematical price of flattening a sphere.