How Big Was the Mongol Empire?

At its height around 1279, the Mongol Empire covered about 27.1 million km², measured from the map outline in TrueSize. That is about 1.6 times modern Russia and nearly 2.8 times the United States. It was widely regarded as the largest contiguous land empire in history, stretching from Korea to Eastern Europe.

The Mongol Empire in 1279 and the 48 contiguous US states (about 8.1 million km²) side by side on the equator, each at its true size.

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The numbers

Region	Area	Ratio to the Mongol Empire
Mongol Empire, 1279 to 1293 (peak)	27.09 million km² (measured in TrueSize)	1
Mongol Empire, 1260s	25.1 million km² (measured in TrueSize)	about 0.93
Modern Russia	about 17.1 million km²	about 0.63
Modern USA	about 9.83 million km²	about 0.36
48 contiguous US states	about 8.1 million km²	about 0.30

The figures depend on how the borders of the khanates are drawn, and published estimates vary. TrueSize uses one consistent outline per year, so you can compare it with other regions on the same terms.

What the map shows

The empire grew under Genghis Khan and his successors in the 13th century, and was divided into several khanates, including the Yuan dynasty in China and the Golden Horde in the west. The peak in the app falls in 1279, after the Mongol conquest of the Song dynasty, and the outline stays similar to 1293.

Much of the Mongol Empire lay in Central and Northern Asia. Mercator maps stretch those high latitudes, so the empire looks even larger than it was, but when you pull it down to the equator beside the 48 contiguous states, the comparison is fair. It is still about 3.4 times their area.

Try it yourself

1. Open the Home tab and click the Modern/Historical switch to open the timeline. Use Go to year and enter 1279.
2. Search for the Mongol Empire. Use the arrow keys to step through earlier and later changes in its borders, or press Play.
3. Pin it, click Today, then add Russia or Contiguous 48 from the search box and drag them side by side.

The timeline works on the web version and in the mobile app. The Stats button on the Tools tab shows the total area of what you have loaded.

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More comparisons

• The largest empires in history, compared
• How big was the Roman Empire?
• How much bigger was the Soviet Union than the USA?
• Historical Borders Map: See Any Country's Borders by Year

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