Using simple terms, you are thinking that Europe is a single country which it isn't. there are 25 different countries in Europe
There are 27 countries in the EU and around 48 in the whole of Europe, the largest being Russia (the part of Russia that is in Europe) and the smallest being the Vatican City.
Although, if the EU gets its way, all those 27 EU countries may one day become one country: a USE (United States of Europe) which would be a disaster.
Britain (
244,820 km²) is just outside the Top 10 - it's in 11th place, a tiny bit smaller than Italy in 10th (
301,318 km²) and a tiny big bigger than Romania (
238,391 km²) in 12th.
Europe has a population of 710 million and the EU has a population of 494 million (compared to only 300 million in the US)
In area, continental Europe is 3,930,000 sq miles, which means it's larger than both Canada and the United States (Canada is 3,854,085 sq miles and the US is 3,718,695
sq mi)
The EU is 1,669,807
sq mi.
The EU is also the world's largest economy - a mammoth $13.881 trillion. The US economy is $13.049 although the US does have a smaller population.
The EU's average GDP per capita is only around 28,000 (Britain is the 6th richest EU country of the 27, with a GDP per capita of $38,624. Only the small nations of Luxembourg, Ireland, Austria, Denmark and Belgium are richer).
That's compared to $35,133 for Canada and over $44,000 for the US.