Luteal Phase Calculator
Calculate your luteal phase length and assess its normality for fertility tracking
Calculate Your Luteal Phase Length
The day you ovulated (use ovulation tests or temperature tracking)
The first day of your period that followed ovulation
Example Calculation
Typical Menstrual Cycle
Cycle length: 28 days
Ovulation date: January 14th (Day 14)
Next period starts: January 28th (Day 28)
Luteal phase calculation: January 28th - January 14th = 14 days
Result
Luteal phase length: 14 days
Status: Normal (within 12-16 day range)
Fertility impact: Optimal for conception and implantation
Menstrual Cycle Phases
Menstrual Phase
Days 1-5
Shedding of uterine lining
Follicular Phase
Days 1-14
Egg development and estrogen rise
Ovulation
Day 14
Egg release from ovary
Luteal Phase
Days 14-28
Progesterone production
Ovulation Tracking Tips
Use ovulation predictor kits (OPKs) for hormone surge detection
Track basal body temperature for sustained temperature rise
Monitor cervical mucus changes (clear, stretchy at ovulation)
Track for at least 3 cycles for pattern recognition
Use fertility tracking apps for comprehensive monitoring
Understanding the Luteal Phase
What is the Luteal Phase?
The luteal phase is the second half of your menstrual cycle, starting right after ovulation and ending when your next period begins. During this phase, the corpus luteum (remnant of the egg follicle) produces progesterone to prepare the uterine lining for potential pregnancy.
Why is Luteal Phase Length Important?
- •Adequate progesterone production for implantation
- •Sufficient time for embryo implantation (6-12 days)
- •Indicator of overall reproductive health
- •Early pregnancy detection timing
Luteal Phase Calculation
Luteal Phase = Period Start Date - Ovulation Date
Normal Ranges
Important: A short luteal phase may indicate luteal phase defect, which can affect fertility and increase miscarriage risk.