Map projections, explained
Every flat map of Earth is telling a small fib somewhere — it has to. This page shows you the different ways mapmakers fib on purpose, and why picking the right map for the job matters more than picking the 'best' one.
What is a map projection?
Picture peeling an orange in one long strip and pressing that peel flat on a table. It won't lie flat without tearing or stretching somewhere — the peel is curved and the table isn't. Earth is the orange. A map projection is the mathematical recipe mapmakers use to squash that peel flat anyway, choosing exactly where the stretching happens.
The four things a map can keep
A map can promise to get certain things right, but never all of them at once. The four things on the table are: how big everything is (area), what shape things are (shape), how far apart things are (distance), and which way is which (direction). Every map protects some of these and gives up on the rest.
The families: cylindrical, pseudocylindrical, conic, azimuthal
Mapmakers usually start by imagining they're wrapping a shape around the globe. Wrap a cylinder around it and you get a cylindrical map, like Mercator. Use a cone and you get a conic map, good for medium-sized regions. Touch it at just one point and you get an azimuthal map, good for looking outward from one city or pole. Pseudocylindrical maps curve those straight cylinder lines into ovals, which is what Equal Earth does.
The kinds: equal-area, conformal, equidistant, compromise
Separately from family, every map has a personality: equal-area maps never lie about size, conformal maps never lie about shape or direction, equidistant maps get distance right from one special point, and compromise maps don't promise anything perfectly but try to keep everything reasonably close to true.
How to choose a projection for the job
Ask what you actually need the map to get right. Coloring countries by population? You need true size, so use an equal-area map. Steering a ship? You need true direction, so use a conformal map. Just want a nice poster of the world? A compromise map looks the most 'normal.' Looking at one place from above? Use an azimuthal map centered there.
Why this site defaults to Equal Earth
This whole site starts every map on Equal Earth because it never cheats on size — a small country stays small, a big one stays big. It bends some shapes near the edges to do that, but that's a far gentler trade than making countries look bigger or smaller than they really are, which is what a lot of maps you've probably already seen end up doing.
Projection
| Projection | True size | True shape | True distance | True direction |
|---|---|---|---|---|
| Equal Earth | Yes | No | No | No |
| Mercator | No | Yes | No | Yes |
| Gall-Peters | Yes | No | No | No |
| Robinson | No | No | No | No |
| Winkel Tripel | No | No | No | No |
| Orthographic | No | No | No | No |
| Azimuthal Equidistant | No | No | Yes* | Yes* |
* Azimuthal equidistant's distance and direction are true only measured from the map's centre point, not between any two arbitrary places.
The seven projections
Every projection this site teaches, one card each.
Equal Earth
Equal Earth is a 2018 equal-area projection that keeps every country at its true relative size, bending shape a little instead — the default map on this site.
Mercator
Mercator is the 1569 conformal projection that keeps compass directions and shapes true everywhere, at the cost of hugely stretching land far from the equator.
Gall-Peters
Gall-Peters is an equal-area projection, first described in 1855 and popularized amid controversy in 1973, that keeps true country size at the cost of badly stretched shapes.
Robinson
Robinson is a 1963 compromise projection, tuned to look visually balanced rather than to preserve any single property exactly, that was National Geographic's standard map from 1988 to 1998.
Winkel Tripel
Winkel Tripel is a 1921 compromise projection, balancing area, direction, and distance error at once, that has been National Geographic’s standard world map since 1998.
Orthographic
Orthographic is a perspective projection that shows Earth as it would look from infinitely far away — one hemisphere at a time, undistorted at the center and compressed toward the edge.
Azimuthal Equidistant
Azimuthal equidistant preserves true distance and direction from a single chosen center point, the projection behind the UN emblem, at the cost of area and shape everywhere else.
Compare them head-to-head
Frequently asked questions
What is a map projection?
A map projection is a mathematical method for turning the curved surface of the Earth into a flat map. Every projection has to distort something — area, shape, distance or direction — because a sphere cannot be flattened without stretching or tearing.
Why can't a flat map of Earth be completely accurate?
Earth's surface is curved, and a mathematical rule called Theorema Egregium proves that a curved surface cannot be flattened onto a plane without distortion. Every flat map has to choose which properties to preserve and which to sacrifice.
What are the main types of map projections?
Projections are grouped by shape into cylindrical, pseudocylindrical, conic and azimuthal families, and by what they preserve into equal-area, conformal, equidistant and compromise types. A projection like Mercator belongs to one of each: cylindrical and conformal.
What's the difference between an equal-area and a conformal map?
An equal-area map, like Equal Earth, keeps every region's true size correct but bends some shapes to do it. A conformal map, like Mercator, keeps shapes and compass directions correct everywhere but lets area balloon far from the equator.
Is there a single most accurate map projection?
No. Every flat projection distorts something, so 'accurate' depends on what you're measuring. Equal Earth is accurate for size, Mercator is accurate for direction, and no projection is accurate for everything at once.
Which map projection should I use for a school project?
For comparing country sizes or population, use an equal-area map like Equal Earth. For a general-purpose world map or poster, a compromise projection like Robinson or Winkel Tripel looks natural without claiming false precision.
Why does Equal Earth School default to the Equal Earth projection?
Equal Earth keeps every country's true relative size honest, which is the property most people misjudge on a world map. It bends some shapes near the poles to do that, a fair trade for a general teaching map.