| Country | Military service age and obligation |
| Brunei | 18 years of age (est.) for voluntary military service; non-Malays are ineligible to serve (2007) |
| Bulgaria | 18-27 years of age for voluntary military service; conscript service obligation - 9 months; as of May 2006, 67% of the Bulgarian Army comprised of professional soldiers; conscription ended as of 1 January 2008; Air and Air Defense Forces and Naval Forces became fully professional at the end of 2006 (2008) |
| Burkina Faso | 18 years of age for compulsory military service; 20 years of age for voluntary military service (2001) |
| Burma | 18 years of age for voluntary military service for both sexes; forced conscription of children, although officially prohibited, reportedly continues (2007) |
| Burundi | 16 years of age for compulsory and voluntary military service; children as young as 10 years of age have been conscripted into the armed forces; the enrollment of children is still not prohibited (2007) |
| Cambodia | conscription law of October 2006 requires all males between 18-30 to register for military service; 18-month service obligation (2006) |
| Cameroon | 18 years of age for voluntary military service; no conscription; the government makes periodic calls for volunteers (2006) |
| Canada | 16-34 years of age for voluntary military service; women comprise approximately 11% of Canada's armed forces (2006) |
| Cape Verde | 18 years of age (est.) for selective compulsory military service; 14-month conscript service obligation (2006) |
| Cayman Islands | void |
| Central African Republic | 18 years of age for compulsory and voluntary military service; 2-year conscript service obligation (2006) |
| Chad | 20 years of age for conscripts, with 3-year service obligation; 18 years of age for volunteers; no minimum age restriction for volunteers with consent from a guardian; women are subject to 1 year of compulsory military or civic service at age of 21 (2004) |
| Chile | 18-45 years of age for voluntary male and female military service, although the right to compulsory recruitment is retained; service obligation - 12 months for Army, 22 months for Navy and Air Force (2008) |
| China | 18-22 years of age for selective compulsory military service, with 24-month service obligation; no minimum age for voluntary service (all officers are volunteers); 18-19 years of age for women high school graduates who meet requirements for specific military jobs (2007) |
| Christmas Island | void |
| Clipperton Island | void |
| Cocos (Keeling) Islands | void |
| Colombia | 18-24 years of age for compulsory and voluntary military service; service obligation - 18 months (2004) |
| Comoros | void |
| Congo, Democratic Republic of the | 18-45 years of age for military service |
| Congo, Republic of the | 18 years of age for voluntary military service; women allowed to serve (2007) |
| Cook Islands | void |
| Coral Sea Islands | void |
| Costa Rica | void |
| Cote d'Ivoire | 18 years of age for compulsory and voluntary military service (2008) |
| Croatia | 18-27 years of age for compulsory military service; 16 years of age with consent for voluntary service; 6-month conscript service obligation; full conversion to professional military service by 2010 (2006) |
| Cuba | 17-28 years of age for compulsory military service; 2-year service obligation; both sexes subject to military service (2006) |
| Cyprus | Greek Cypriot National Guard (GCNG): 18-50 years of age for compulsory military service for all Greek Cypriot males; 17 years of age for voluntary service; females are not conscripted; age of military eligibility 17 to 50; length of normal service is 25 months with a minimum of 3 months (2006) |
| Czech Republic | 18-28 years of age for voluntary and 19-28 for compulsory military service (2008) |
| Denmark | 18 years of age for compulsory and voluntary military service; conscripts serve an initial training period that varies from 4 to 12 months according to specialization; reservists are assigned to mobilization units following completion of their conscript service; women eligible to volunteer for military service (2004) |
| Dhekelia | void |
| Djibouti | 18 years of age for voluntary military service; 16-25 years of age for voluntary military training; no conscription (2008) |
| Dominica | void |
| Dominican Republic | 18 years of age for voluntary military service (2007) |