Period Tools — Period Calculator - Showcase Project
Listed August 29, 2026
About Period Tools — Period Calculator
Predict your next 6 periods, ovulation day and fertile window
Period Tools is a free period and ovulation calculator. Enter the first day of your last period and your usual cycle length, and it projects your next six cycles, your estimated ovulation day, and the fertile window around it. It is built for the common real-world case where cycles are not textbook 28 days — you set your own cycle and period length, and the projection adjusts rather than assuming an average. Alongside the calculator there are cycle-tracking guides and a printable calendar view. No account, no app to install, and nothing you enter is stored.
Project details
Website: https://periodtools.com