By the early 20th century France and most other European nations had largely completed a population transition. Following high birthrates and death rates up to the 17th century, France had a rapidly falling death rate. The rate fell due to such factors as improved public health measures, medical advances, and increased food production. However, the birthrate remained high into the 19th century, and population increased at an unprecedented speed.

Because France is large and, by European standards, sparsely populated, most of its population gain could be absorbed internally. As a result, France did not participate heavily in the waves of emigration that affected other European countries. Nevertheless, French settlement in North America resulted at least partially from population pressures at home.

The growth of cities and industrial employment, along with the passage of child labor laws and the beginnings of social security systems, gradually discouraged French citizens from having large families. Birthrates began to decline in France and again reached virtual equality with death rates by the early 20th century. By the 1930s the French birthrate had fallen so low that the government passed legislation in 1938 to encourage population growth. This legislation, providing such benefits as family allowances and medical and educational aid, was still in effect in the 1990s. Despite these efforts, however, population growth in France has continued at a slow rate. Experts predict that the population will probably remain at about its present level into the 21st century.

In the early 1990s France had an annual birthrate of less than 14 per 1,000 population and a death rate of about 9 per 1,000. About 42 percent of the people were under 30 years old; 22 percent were between the ages of 30 and 44; 16 percent were between 45 and 59; and 20 percent were more than 60. In Western Europe, France is the fourth most populous country, narrowly trailing Germany, Italy, and Great Britain, and far ahead of Spain and Portugal.

In 1990 France ranked as the 18th most populous nation in the world. Its position is steadily declining because of the population increases in the developing nations of Africa, Asia, and Latin America. France was the fifth most populous nation in 1936, but it may be no higher than 25th by the year 2000.

France's large area makes its population density relatively low about 270 persons per square mile (104 persons per square kilometer). Led by The Netherlands, the major European nations are much more crowded. Within France, the population density varies widely depending on topography, urbanization, and economic opportunities.