Los Angeles County had the highest GDP (US dollars) of 58 counties in 2018, at $755.37 billion. Sierra County had the lowest, at $97.09 million. The median was $8.83 billion and the figure for California was $2.9 trillion. Source: the U.S. Bureau of Economic Analysis.
GDP at current prices, millions of US dollars. United States: Bureau of Economic Analysis GDP by state (the national figure is the total of the same table) and GDP by county. Other countries and the World: World Bank, converted from national currency at official annual average exchange rates.
US dollars, for the United States, its states and counties, and for every country and the World from the World Bank. For Spain and the EU in euros use gdp. Exchange rate swings move dollar values even when output does not.
Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.
How to cite
U.S. Bureau of Economic Analysis. CAGDP1: county GDP summary, current-dollar GDP (published in thousands of dollars, shown in millions). https://apps.bea.gov/regional/zip/CAGDP1.zip. Retrieved 2026-10-08.
Use this data in your AI agent
Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:
Rank Counties in California by GDP (US dollars) using official data, and cite the source.
rank_places {"indicator":"gdp_usd","level":"province","within":"California","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=gdp_usd&level=province&within=California&limit=10
Los Angeles County, with $755.37 billion in 2018, according to the U.S. Bureau of Economic Analysis.
Which county has the lowest GDP (US dollars)?
Sierra County, with $97.09 million in 2018.
Where does this ranking come from?
Every value comes from one source and one period, so the places are comparable: U.S. Bureau of Economic Analysis, CAGDP1: county GDP summary, current-dollar GDP (published in thousands of dollars, shown in millions). Retrieved 2026-10-08.
Gross domestic product (GDP), US dollars: other rankings
