Luteal Phase Calculator
Calculate the length of your luteal phase — the second half of your cycle from ovulation to the next period.
What is Luteal Phase?
The luteal phase runs from ovulation to the start of the next period. A typical luteal phase is 12–14 days. Phases shorter than 10 days may indicate luteal-phase deficiency, which can affect implantation and fertility. Tracking your basal body temperature or LH surge confirms ovulation timing.
How is it calculated?
Luteal Phase Length = Cycle Length − Day of Ovulation. Categories: < 10 days short, 10–16 days normal, > 16 days long.
Frequently Asked Questions
- How can I detect ovulation?
- Cervical mucus, BBT, ovulation predictor kits.
- Does luteal phase change?
- It is more consistent than the follicular phase.
- What if my luteal phase is short?
- Discuss with a fertility specialist if trying to conceive.