Resources Ovulation Calculator March 8, 2016 5559 Facebook Twitter Google+ Pinterest WhatsApp Find out when you’re likely to ovulate & increase your chances of getting pregnant by using our ovulation calculator. Simply enter the first day of your last period and your menstrual cycle length then calculate. Please select the first day of your last menstrual period: JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember / 12345678910111213141516171819202122232425262728293031 / 2023202420252026202720282029203020312032203320342035203620372038203920402041204220432044204520462047204820492050 Usual number of days in your cycle: 2021222324252627282930313233343536373839404142434445