How much does Mercator enlarge area?

On a spherical Mercator map, the local area scale at latitude 60° is four times the scale at the equator. By 80°, it is about 33 times as large. That scale change is why a northern country can dominate the page without dominating the Earth’s surface.

Close view of a globe around the Arctic and northern latitudes — Latitude, rather than a country’s actual area, controls Mercator’s local enlargement.

The scale by latitude

Mercator stretches distances equally in the east–west and north–south directions at any one point. On a spherical model, each distance scale is 1 ÷ cos(latitude), so the local area factor is 1 ÷ cos²(latitude). These values compare a tiny patch at each latitude with a tiny patch at the equator; they are not whole-country area multipliers.

Calculated from 1 ÷ cos²(latitude), rounded to two decimals. North and south latitudes have the same factor.
Latitude	Local area scale	What one equatorial map unit becomes
0°	1.00×	No local enlargement
15°	1.07×	1.07 times the drawn area
30°	1.33×	1.33 times the drawn area
45°	2.00×	2.00 times the drawn area
60°	4.00×	4.00 times the drawn area
70°	8.55×	8.55 times the drawn area
80°	33.16×	33.16 times the drawn area

The factor rises without a finite limit toward 90°. A full Mercator map therefore cannot show the poles at a finite height. This site caps the visible Mercator latitude range to keep the world usable on screen.

Seven places on this map

The table applies the same formula to each place’s representative map anchor in our Natural Earth file. An anchor is one point used to position the movable outline. It is not the average latitude of the country, and a large place such as Russia spans many local scale factors.

Our calculation from the saved anchor coordinates; the factor describes a small patch at that point, not the entire country.
Mapped place	Anchor latitude	Local area factor	Map view
Indonesia	1.0°S	1.00×	Explore
Brazil	12.1°S	1.05×	Explore
India	22.7°N	1.17×	Explore
Japan	36.1°N	1.53×	Explore
United Kingdom	54.4°N	2.95×	Explore
Canada	60.3°N	4.08×	Explore
Greenland	74.3°N	13.69×	Explore

At Greenland’s anchor, the factor is about 13.69×; at India’s it is about 1.17×. That does not mean Greenland’s whole outline is 13.69 times its real area on the map. Every part of each outline has its own latitude. The point values explain the direction and strength of the distortion without pretending to measure a whole country from one coordinate.

Which view answers which question?

Use Mercator to see the familiar distortion and to compare how an outline changes when moved north or south. Use Equal Earth when the visual question is relative area: it maintains one area scale across latitudes, although it changes shapes. Use the fixed area figures for a numerical comparison. For example, our Greenland–India comparison remains the same whichever projection you choose.

The mathematical property follows the PROJ Mercator documentation. The U.S. Geological Survey explains the wider trade-off between area, shape and direction. Our anchor coordinates and country boundaries come from the site’s prepared Natural Earth 1:50m dataset.