Equal Earth vs Gall-Peters
Equal Earth and Gall-Peters, measured item by item. Every figure below is labelled with the projection whose equator it is normalised to.
What each one is
| Property | Equal Earth | Gall-Peters |
|---|---|---|
| Family | Equal-area pseudocylindrical | Equal-area cylindrical |
| Axis held at 1.00 | Area | Area |
| Leads with | Shape distortion | Shape distortion |
| True-shape parallel | 40.4° | 45.0° |
| Aspect ratio | 2.055 : 1 | 1.571 : 1 |
| Pole drawn as a line | 59% of the equator | As long as the equator |
The same parallel, under each
Six parallels, two axes. The area columns are normalised to that projection's own equator; the shape columns are the ratio of the Tissot indicatrix's axes at the same point, where 1.00 means the shape there is unchanged. Each projection reads against its own baseline, so the two area figures on a row are not two readings on one axis.
| Latitude | Equal Earth area | Gall-Peters area | Equal Earth shape | Gall-Peters shape |
|---|---|---|---|---|
| 0° | 1.00 | 1.00 | 1.35 | 2.00 |
| 30° | 1.00 | 1.00 | 1.15 | 1.50 |
| 45° | 1.00 | 1.00 | 1.09 | 1.00 |
| 60° | 1.00 | 1.00 | 1.69 | 2.00 |
| 72° | 1.00 | 1.00 | 3.43 | 5.24 |
| 84° | 1.00 | 1.00 | 24.6 | 45.8 |
What they disagree about most
The objects Equal Earth and Gall-Peters treat most differently. The first two columns stand alone: each is the area that object is painted at under that projection, against that projection's own equator. The third is the ratio between them.
Once more, because it matters: the Equal Earth multiples are normalised to Equal Earth's equator and the Gall-Peters multiples to Gall-Peters's. The two do not share an axis. What the third column exactly means is this - print both maps with equators the same length, and this shape comes out that many times larger on the first than on the second. It is a checkable statement about two pictures, not a physical quantity.
| Object | Equal Earth area | Gall-Peters area | Equal Earth ÷ Gall-Peters |
|---|---|---|---|
| Belgium | 1.00 | 1.00 | 1.00 |
| Denmark | 1.00 | 1.00 | 1.00 |
| Latvia | 1.00 | 1.00 | 1.00 |
| Slovenia | 1.00 | 1.00 | 1.00 |
| New Zealand | 1.00 | 1.00 | 1.00 |
| Bosnia and Herzegovina | 1.00 | 1.00 | 1.00 |
| Estonia | 1.00 | 1.00 | 1.00 |
| Moldova | 1.00 | 1.00 | 1.00 |
Area multiples are integrated over the whole polygon as drawn, not estimated from a centroid latitude. Shape ratios are taken at the object's anchor.
Which to use
Both hold area, and both hold it exactly: the area axis is 1.00 at every latitude on each, with nothing between them. So the entire difference in this pairing is shape.
Which means comparing them is comparing purpose and taste rather than accuracy. Read the shape columns: on a given parallel, whichever stretches the outline more is the one paying more there.
If sizes are going to be read off the page, both of these qualify. Which one to pick depends on which outline you are willing to look at.
See it in the tool
Switching projections in the tool morphs the map between the two - it interpolates projected pixel coordinates, so which places shrink and which swell is visible at a glance. It is the fastest way on this site to understand what separates a pair.