The number of speakers given varies widely according to the sources. The total in Ethnologue 16 is 10 million, mostly based on figures published 1987–2002, but with a few dating from the 1960s. The figure for Imbabura Quechua in Ethnologue, for example, is 300,000, an estimate from 1977. The missionary organization FEDEPI, on the other hand, estimated one million Imbabura speakers (published 2006). Census figures are also problematic, due to under-reporting. The 2001 Ecuador census reports only 500,000 Quechua speakers, where most sources estimate over 2 million. The censuses of Peru (2007) and Bolivia (2001) are thought to be more reliable.
- Argentina: 900,000 (1971)
- Bolivia: 2,100,000 (2001 census); 2,800,000 South Bolivian (1987)
- Chile: few if any
- Colombia: 25,000 (2000–2007)
- Ecuador: 2,300,000 (Adelaar 1991)
- Peru: 3,260,000 (2007 census); 3,500,000 to 4,400,000 (Adelaar 2000)