By proportion

Countries with the greatest proportion of Christians (as of 2002):

1. Poland, 96%
2. Ireland, 95%
3. Argentina, 94% (mostly Roman Catholic, Jewish 2%)
4. Spain, 94%
5. France, 90% (Muslim 7%, Jewish 1%)
6. United States, 84% (Jewish, 2%)
7. Brazil, 80%
8. United Kingdom, 69% (Muslim 2.5%, Hindu 1.6%, Jewish 0.6%)
9. Germany, 68% (Muslim 3.7%)
10. South Africa, 68% (indigenous and animist 28%, Muslim 2%, Hindu 1.5%)
11. Nigeria, 40% (Muslim, 50%)
12. Sudan, 5% (Muslim 70%)
13. Iraq, 3% (Muslim, 97%)
14. Mali, 1% (Muslim, 90%)

Countries with the greatest proportion of Muslims (as of 2002):

1. Saudi Arabia, 100%
2. Turkey, 99.8%
3. Afghanistan, 99% (80% Sunni, 19% Shi'a)
4. Algeria, 99%
5. Iran, 98%
6. Pakistan, 97%
7. Iraq, 97% (Christian, 3%)
8. Mali, 90% (indigenous 9%, Christian 1%)
9. Indonesia, 88% (Christian 8%, Hindu 2%, Buddhist 1%)
10. Sudan, 70% (indigenous 25%, Christian 5%)
11. Nigeria, 50% (Christian, 40%)
12. India, 11% (Hindu 82%, Christian 2%)

Countries with the greatest proportion of Hindus (as of 2002):

1. Nepal 89.5%
2. India, 82% (Muslim 11%, Christian 2%)
3. Fiji, 75% (Muslim 16%, Christian 6%) [that figure refers to Indo-Fijians who make up 44% of the population, while ethnic Fijians are mostly Christian acc. to: Fiji ]
4. Mauritius, 50%
5. Bhutan, 25%
6. Bangladesh, 16%
7. Sri Lanka 15%
8. Indonesia, 7%
9. Pakistan, 3%
10. United Kingdom 1.6%
11. South Africa, 1.5%

Countries with the greatest proportion of Buddhists (as of 1999):

1. Japan, Shinto and Buddhist 84%
2. Sri Lanka, 70% (Hindu 15%, Christian 8%, Muslim 7%)

Countries with the greatest proportion of Jews (as of 2000):

1. Israel, 80% (Muslim 14%, Christian 2%)

By population

Largest Christan populations (as of 2002):

1. United States, 189,983,000
2. Brazil, 170,405,000
3. Mexico, 96,614,000
4. China, 86,801,000
5. Philippines, 72,225,000
6. Germany, 60,712,000
7. Nigeria, 54,012,000
8. Italy, 47,704,000
9. France, 45,505,000
10. Congo, 42,283,000

Largest Muslim populations (as of 2002):

1. Indonesia, 182,570,000
2. Pakistan, 134,480,000
3. India, 121,000,000
4. Bangladesh, 114,080,000
5. Turkey, 65,510,000
6. Iran, 62,430,000
7. Egypt, 58,630,000
8. Nigeria, 53,000,000
9. Algeria, 30,530,000
10. Morocco, 28,780,000

Largest Hindu populations (as of 2003):

1. India, 866,000,000
2. Nepal, 23,300,000
3. Bangladesh, 22,600,000
4. Indonesia, 4,800,000
5. Sri Lanka, 3,000,000
6. Mauritius, 650,000
7. United Kingdom, 500,000
8. Fiji, 335,000
9. Trinidad & Tobago, 261,000
10. Suriname, 120,000

Sources

• http://www.aneki.com/lists.html
• http://www.odci.gov/cia/publications/factbook/