← Back to Cycle Directory Hub
27 Day Cycle Overview
Ovulation: Day 13

High Fertility: Day 814 | Next Period: Day 28

Your Fertile Window Explained

Because the luteal phase (post-ovulation) is almost always 14 days, a 27-day cycle means you ovulate around Day 13. Sperm can survive up to 5 days internally, meaning your highest chances of conception fall exactly between Day 8 and Day 14.

Your Specific Cycle Metrics

Cycle DayBiological Event
Day 1First day of period (Full Flow)
Day 8 - 14High Fertility Window
Day 13Estimated Ovulation
Day 28Next expected period / Testing Day

Compare Other Cycle Lengths

Trending Calculations Today

Updated Daily