China and India are the two biggest rice producers in the world, growing 204 and 159 million metric tons respectively in 2013, more than half of total world production. The major rice-growing countries are all in Asia; the largest producer outside that region is Brazil, with 12 million metric tons. The top exporters are India and Thailand, selling rice for $7.9 billion and $5.4 billion respectively.
Rice is the most important grain for human consumption in the world, being a staple in the diet of more than half of global population. Over 20 percent of calories consumed worldwide come from rice.
It originated in Asia, which still accounts for around 90 percent of production. Examples of important rice-growing countries outside Asia are Brazil, the United States, Egypt and Nigeria. Most rice grown is consumed locally; only around 6 percent is sold on the world market.
There are over 40.000 varieties of rice, such as various types of sticky rice popular in many Southeast Asian countries, and strains that are colored red and black. It is traditionally cultivated in flooded fields. It needs a tropical or subtropical climate to grow. In the United States, rice has been cultivated since the 17th century.