Background: The demographic dividend, defined as the economic growth potential resulting from favorable shifts in population age structure following rapid fertility decline, has been widely employed to advocate improving access to family planning. The current framework focuses on the long-term potential, while the short-term benefits may also help persuade policy makers to invest in family planning. Methods: We estimate the short- and medium-term economic benefits from two major family planning goals: the Family Planning 2020 (FP2020)'s goal of adding 120 million modern contraceptive users by 2020; Sustainable Development Goals (SDG) 3.7 of ensuring universal access to family planning by 2030. We apply the cohort component method to World Population Prospects and National Transfer Accounts data. India and Nigeria, respectively the most populous Asian and African country under the FP2020 initiative, are used as case studies. Results: Meeting the FP2020 target implies that on average, the number of children that need to be supported by every 100 working-age people would decrease by 8 persons in India and 11 persons in Nigeria in 2020; the associated reduction remains at 8 persons in India, but increases to 14 persons in Nigeria by 2030 under the SDG 3.7. In India meeting the FP2020 target would yield a saving of US$18.2 billion (PPP) in consumption expenditures for children and youth in the year 2020 alone, and that increased to US$89.7 billion by 2030. In Nigeria the consumption saved would be US$2.5 billion in 2020 and $12.9 billion by 2030. Conclusions: The tremendous economic benefits from meeting the FP2020 and SDG family planning targets demonstrate the cost-effectiveness of investment in promoting access to contraceptive methods. The gap already apparent between the observed and targeted trajectories indicates tremendous missing opportunities. Accelerated progress is needed to achieve the FP2020 and SDG goals and so reap the demographic dividend.