According to the US Census Bureau, there are 97.2 males for every 100 female in the USA.

In general Western states have the highest male to female ratios, while states in the Mid Atlantic and Deep South have more women than men. 39 states have more females than males, while 10 have more males. California is the only state with exactly one male for every female. Illinois exactly matches the national average with 97.2 males for every 100 female.

There are only 89.7 males for every 100 females in the District of Columbia this is far lower than any state. Rhode Island and Maryland both have 93.8 men for every 100 women, the fewest of any states.

At the other extreme, Alaska has 108 males for every female, the most of any state. Nevada comes in second with 103.8 males for every female.

In the US approximately, 105 boys are born for every girl. However, at any given age more males die then females. There are more males than females in every age group up until 40. After that age females outnumber men. There are only 38 men older than 90 for every 100 females.

Worldwide there are approximately 101.4 males for every 100 females. 106.4 males are born for every female. There more males than females in every five year age bracket until 40-45 years of age. Every age group from 45-50 and older has more females than males.

Male to female ratios vary significantly between countries. Migration is a major source of this variance. The oil producing countries of the Persian Gulf have the highest male to female ratios in the world, due to the high number of male immigrants. There are 187 males for every 100 females in Qatar

At the other extreme several former Soviet countries have the lowest male to female ratios in the world, due to a large number of men who have sought work in other countries. Estonia has 84 males for every female, while Russia has only 86.

The two most populous countries on earth have very high male to female ratios as a result of societal preferences for sons over daughters. In both countries many female fetuses are aborted. In addition young females have higher mortality rates in families that favor sons over daughters. In both countries there are 106 males for every female.