How Big Was the Roman Empire Compared to Today's Countries?

At its peak in 116 AD, the Roman Empire covered about 4.83 million km², measured from the map outline in TrueSize. That is about half the area of the United States (9.8 million km²), or about 60% of the 48 contiguous states shown in the picture, and a little over the size of the European Union today. Rome ruled many millions of people, but its land area was smaller than most people expect.

The Roman Empire in 116 AD and the 48 contiguous US states side by side on the equator, each at its true size.

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The numbers

Region	Area	Source
Roman Empire, peak, 116 AD	4.83 million km²	measured in TrueSize
Roman Empire, 117 to 269 AD	4.37 million km²	measured in TrueSize
Modern USA	about 9.83 million km²	official total
Contiguous 48 US states	about 8.1 million km²	official total
Modern China	about 9.6 million km²	official total
Modern India	about 3.3 million km²	official total

The USA is about twice the area of the Roman Empire at its peak, and the 48 contiguous states are about 1.7 times its area. India alone is about two thirds of it. Published estimates of Roman territory vary with how historians treat client states and frontier zones, so treat these figures as approximate.

Why the empire looks bigger on maps

The Roman Empire surrounded the Mediterranean, so most of it lay in a band between about 30 and 55 degrees north. Mercator maps stretch those latitudes more than the equatorial zone, and they make Europe look larger against Africa and India.

The empire at its peak, over today's map.

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Try it yourself

1. Click the Modern/Historical switch on the Home tab to open the timeline, then use Go to year to jump to 116.
2. Search for the Roman Empire in the search box. In Historical mode, search shows only what existed in that year.
3. Pin it so it keeps its year, click Today, search for Contiguous 48, and drag both to the equator side by side.

The timeline works on the web version and in the mobile app.

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More comparisons

• How much bigger was the Soviet Union than the USA?
• The Mongol Empire at true size
• The largest empires in history
• Historical Borders Map: See Any Country's Borders by Year

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