Using data from 20 recent Demographic and Health Surveys (Armenia 2005, Azerbaijan 2006, Bangladesh 2004, Colombia 2010, Dominican Republic 2002, Egypt 2008, India 2005-06, Indonesia 2007, Jordan 2007, Kenya 2003, Malawi 2004, Moldova 2005, Morocco 2003-04, Peru 2004-08, Philippines 2003,
Tanzania 2004-05, Turkey 2003, Ukraine 2007, Vietnam 2002, and Zimbabwe 2005-06), we estimate 1) the impact of contraceptive failure on unintended births and induced abortions, and 2) levels of unintended births and induced abortions that could be achieved if current family planning users adopted more effective contraceptive methods. We use multiple-decrement life tables to calculate contraceptive failure rates and simulate alterations of the contraceptive method mix in each country. Results show the contribution of contraceptive failure to unintended births and induced abortions to be substantial. On average, 31% of births from unintended pregnancies and 53% of induced abortions resulted from contraceptive failure. Simulations show that if all women who currently use contraceptives began using the most effective (long-acting or permanent) method to meet their fertility intentions, the level of unintended births would decrease by an average of 27%, and the level of induced abortion could be cut in half.