Pregnancy Calculator & Fertile Window
Enter the first day of your Last Menstrual Period (LMP) to calculate your estimated due date and see your best fertile days to conceive.
What is a Fertility Calculator?
A fertility calculator is a tool that estimates when you are most likely to ovulate based on the length of your menstrual cycle and the first day of your last menstrual period (LMP). Since ovulation — the release of an egg from the ovary — is the most fertile time of the cycle, timing intercourse during this period increases the chance of pregnancy.
How Does the Fertility Calculator Work?
The calculator estimates your ovulation day, usually about 14 days before your next period, and highlights a fertile window of about 6 days. This window includes the 5 days before ovulation and the day of ovulation itself, as sperm can survive inside the female reproductive tract for up to 5 days.
Why Use a Fertility Calculator?
- Improve chances of conception: Knowing your fertile window helps you plan intercourse during your most fertile days.
- Understand your menstrual cycle: Track cycle irregularities or changes over time.
- Natural family planning: Some use it as a method to avoid pregnancy by knowing when to abstain.
How to Use a Fertility Calculator?
- Enter the first day of your last menstrual period (LMP).
- Input your average cycle length (typically 28 days, but varies).
- The calculator will estimate your ovulation date and fertile window.
Signs of Ovulation
Besides using a fertility calculator, you can also watch for ovulation signs such as:
- Change in cervical mucus to a clear, stretchy consistency.
- Mild pelvic or abdominal pain (mittelschmerz).
- Slight increase in basal body temperature.
Limitations
Fertility calculators provide estimates based on averages and assumptions. They work best for women with regular cycles. For irregular cycles or fertility concerns, consult a healthcare professional or consider ovulation predictor kits and fertility monitoring devices.
