# Equal-Area vs Compromise Projections: Which One Does Your Map Actually Need?

The UN recommended equal-area projections, but equal-area is not automatically right for every map. A decision guide covering Equal Earth, Natural Earth, Robinson and when each one wins.

> Editor: https://ohmymaps.com/ · Versão em página: https://ohmymaps.com/blog/equal-area-vs-compromise-map-projections/

After the UN General Assembly
[recommended equal-area projections in September 2026](/blog/un-equal-earth-map-resolution/),
the obvious conclusion to draw is that equal-area maps are correct and everything
else is a mistake. That conclusion is too strong, and acting on it will make some
of your maps worse.

The resolution was aimed at a specific failure: general-purpose maps that use a
navigation projection and therefore misrepresent how big places are. It was not
a claim that area is the only property worth preserving. Here is how to tell
which family your map belongs to.

## The three families

Every world projection in common use falls into one of three groups, and the
group tells you what the map can be trusted about.

**Equal-area (equivalent).** Area is exact everywhere. Shape is sacrificed.
Examples: Equal Earth, Eckert IV, Mollweide, Gall-Peters.

**Conformal.** Local shape and angle are exact. Area is sacrificed, badly.
Example: Mercator. There is essentially one that matters for world maps, and it
is a navigation tool.

**Compromise.** Nothing is exact, everything is close. Examples: Natural Earth,
Robinson, Winkel Tripel, Miller. These are designed by eye to look right rather
than to satisfy a constraint.

Note where the UN's own cartographers sit. The Secretariat has historically used
Robinson, Winkel Tripel and Eckert IV, so two of its three habitual projections
are compromise projections, not equal-area ones. The resolution recommends a
direction to the world; it did not audit the UN's own back catalogue.

## The one question that decides it

**Will a reader compare the size of two shaded regions and draw a conclusion
from the comparison?**

If yes, use equal-area. If no, a compromise projection is usually the better
map.

That is genuinely most of the decision. The rest is refinement.

## Use equal-area when

- **The value is per unit of ground.** Population density, land use, forest
  cover, emissions per square kilometre. The reader is doing area arithmetic
  whether they know it or not.
- **The map is teaching.** This is the case the resolution names. A map in front
  of a student who has no way to correct for the projection should not be
  quietly making a size argument.
- **Size is the point.** Territory held, area burned, coverage gained, land
  under some designation.
- **Someone will screenshot it into an argument.** If the map is going to be
  passed around detached from your caption, it needs to survive without one.

## Use a compromise projection when

- **The map is categorical, not quantitative.** Countries you have visited,
  offices you operate, members of an alliance. Nobody reads relative area off a
  map like that, and Natural Earth will look better than Equal Earth doing it.
- **Recognisability matters more than measurement.** A slide, a header image, a
  poster. Compromise projections keep coastlines looking like the coastlines
  people have memorised.
- **The map is regional.** Over a single country or continent, the difference
  between projection families shrinks a great deal, and other properties start
  to dominate the choice.

## Use Mercator when

Navigation, and layouts that must line up with web map tiles. That is the list.
The UN text carves out exactly this case and no more.

## Quick reference

<div class="table-scroll">

| Your map is                          | Use                        | Because                                   |
| ------------------------------------ | -------------------------- | ----------------------------------------- |
| a choropleth of a per-area value     | Equal Earth                | area comparison must be honest            |
| classroom or textbook material       | Equal Earth                | the reader cannot correct for distortion  |
| countries visited, offices, alliances | Natural Earth              | categorical, and it simply looks better   |
| a report or a slide                  | Robinson or Natural Earth  | familiar outlines, no measurement claim   |
| a navigation chart                   | Mercator                   | straight line equals constant bearing     |
| about one hemisphere                 | Orthographic               | a globe is honest about being a globe     |

</div>

## The cheapest way to decide

Do not decide up front. Build the map in Natural Earth, which is the default,
then switch the projection once the data and colours are in place. Switching
re-renders the same document: your regions, labels, legend and imported values
all survive it.

Then look at the result and ask whether the map is making a claim about size. If
it is, keep Equal Earth. If it is not, keep the one that looks better. Ten
seconds of clicking beats a paragraph of theory, including this one.

<div class="cta">
  <p><strong>Compare them side by side.</strong> Build your map once, then cycle through the projections before you export.</p>
  <a class="cta-button" href="https://ohmymaps.com/">Open the editor</a>
</div>

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Related reading:
[What is the Equal Earth projection?](/blog/equal-earth-projection-explained/)
and the full walkthrough of every projection in the editor,
[Which map projection should you use?](/blog/which-map-projection-should-you-use/).