You’ve played the word game — if California was a separate country, it would be the Xth largest economy in the world.
The Economist magazine has revised the game with a graph that matches the GDP of each state with another country with the closest GDP. Map is here. The ‘population’ button at the top changes the map to match each state with a country with the closest population size.
A few fun observations:
The Economist points out that even with Michigan’s troubles in car manufacturing, their GDP is comparable to Taiwan.
I noted that Russia has a GDP comparable to Texas. Poland has a population comparable to California and GDP comparable to Virginia. Saudi Arabia has a population comparable to Texas and GDP comparable to Massachusetts.
Back to the old game — If California was a separate country, it would be the 8th largest economy in the world. Texas would be the 13th largest. (I combined the Economist map with Wikipedia data and excluded the combined European Union amount so your results may vary.)