Health

Luteal Phase Calculator

Determine your luteal phase length and what it means for fertility.

About the Luteal Phase

The luteal phase spans from ovulation to the start of the next menstrual period. A normal luteal phase is 10–16 days (average 14). A short luteal phase (<10 days) may indicate insufficient progesterone production, potentially affecting embryo implantation. Consistent short luteal phases warrant medical evaluation for fertility concerns.