The total population of Yemen is 28,915,284 people. The people of Yemen speak the Arabic language. Yemen's linguistic diversity is nearly homogeneous according to a fractionation scale, which is 0.008 for Yemen. The average age is about 18.6 years. Life expectancy in Yemen is 64. Female fertility rate in Yemen is 4.4. About 15% of Yemen's population is obese. Ethnic diversity is nearly uniform according to a fractionation scale, which is 0 for Yemen. Details of the language, religion, age, gender distribution and advancement of the people of Yemen can be found in the sections below, as well as the section on education in the country.

Population
In Yemen, the population density is 54 people per square kilometer (140 per square mile). Based on these statistics, this country is considered sparsely populated. The total population of Yemen is 28,915,284 people. Yemen has approximately 273,000 foreign immigrants. Immigrants in Yemen account for 0.2 percent of the total number of immigrants worldwide. Immigrants in Yemen account for 1.3 percent of the total number of immigrants worldwide. Yemen's ethnic diversity is nearly uniform according to an ethnicity-based fractionation scale. Ethnic Fractionation (EF) deals with the number, size, socioeconomic distribution, and geographic location of diverse cultural groups, usually within a state or some other demarcated area. Specific cultural characteristics can refer to language, skin color, religion, ethnicity, customs and traditions, history, or other distinctive criteria, alone or in combination. These characteristics are often used for social exclusion and power monopolization. The index of ethnic fractionation in Yemen is 0. This means that people living in Yemen are somewhat fractionated. EF is usually measured as 1 minus the Herfindahl concentration index of ethnolinguistic group proportions, which reflects the probability that two randomly drawn individuals from the population belong to different groups. The theoretical maximum of EF of 1 means that each person belongs to a different group. Below are statistics of Yemen on average age and gender distribution at different ages.

Old
The average age is about 18.6 years. The average age for men is 18.5 and the average age for women is 18.7.

Gender
The sex ratio, or number of males per female (estimated at birth), is 1.05. It can be further broken down into the following categories: sex ratio below 15 - 1.04; sex ratio from 15 to 64 - 1.03; sex ratio over 64 - 0.92; Overall sex ratio - 1.03. The overall sex ratio differs from the sex ratio estimated at birth. This is because some newborns are included in the sex ratio estimated at birth, but die within the first few weeks of life and are not included in the overall sex ratio.