Contraceptive prevalence is the percentage of women who are currently using, or whose sexual partner is currently using, at least one method of contraception, regardless of the method used. It is usually reported for married or in-union women aged 15 to 49.

The indicator is calculated from nationally representative household surveys with questions on current use of contraception. Surveys that commonly include this information are: Demographic and Health Surveys (DHS), Fertility and Family Surveys (FFS), Reproductive Health Surveys (RHS), Multiple Indicator Cluster Surveys (MICS), other international survey programmes and national surveys. On average, surveys are undertaken every three to five years.

World Contraceptive Use 2012 provides information on the source of each data point (usually denoted by an acronym). A description of each acronym is given in the worksheet labeled "Sources". For surveys that are not part of an international survey programme, the full name is provided in the field "Survey name".

Contraceptive prevalence is useful for tracking progress towards the target of achieving universal access to reproductive health, especially when the indicator is considered in conjunction with other information about women’s knowledge of family planning or accessibility and quality of family planning services. Information on contraceptive prevalence complements the indicator of unmet need for family planning. The sum of contraceptive prevalence and unmet need indicates the total demand for family planning. The proportion of demand for family planning satisfied is computed by dividing contraceptive prevalence by total demand for family planning.

For analytical purposes, contraceptive methods are often classified as either modern or traditional. Modern methods of contraception include female and male sterilization, oral hormonal pills, the intra-uterine device (IUD), the male condom, injectables, the implant (including Norplant), vaginal barrier methods, the female condom and emergency contraception. Traditional methods of contraception include rhythm (periodic abstinence), withdrawal, prolonged abstinence, breastfeeding, douching, lactational amenorrhea method (LAM) and folk methods. The sum of unmet need for family planning and prevalence of traditional methods indicates the level of unmet need for modern methods.

Differences in the survey design and implementation, as well as differences in the way survey questionnaires are formulated and administered, can affect the comparability of data over time and between countries. One of the most common differences relates to the range of contraceptive methods included and the existence or not of probe questions regarding the types of methods used. The lack of probe questions, asked to ensure that the respondent understands the meaning of the different contraceptive methods, can result in an underestimation of contraceptive prevalence.

The characteristics (age, sex, marital or union status) of the persons for whom contraceptive prevalence is measured can also affect the comparability of data on contraceptive prevalence. Illustrations of alternative reference populations that are sometimes used are sexually active women (irrespective of marital status) or ever-married women.

The time frame used to assess contraceptive prevalence can also vary. Often it is left to the respondent to determine what is meant by “currently using” a method of contraception. Some surveys ask about use within the past month. Occasionally, when information on current use is not collected, data on use of contraceptive methods at last sexual intercourse or during the previous year are utilized. Notes are used to indicate any differences between the data presented in World Contraceptive Use 2012 and the standard definition of contraceptive prevalence given above.

Generally, there is no discrepancy between data presented in World Contraceptive Use 2012 and contraceptive prevalence published in survey reports. However, some published national data on contraceptive prevalence have been adjusted by the United Nations Population Division to improve comparability. Notes are used to indicate when adjustments were made.

World Contraceptive Use 2012 contains 934 observations on contraceptive use for 194 countries or areas. All countries or areas that do not have any observed data on contraceptive prevalence in the data base had total populations of less than one million people in 2010, except for Cyprus. The data base presents data available as of July 2012.