Are you curious to know when you were conceived? Our Pregnancy Calculator & Ovulation Estimator can help you estimate your conception date based on your birthdate! It's also known as a reverse due date calculator. By inputting your birthdate (or the due date if you know it), the calculator estimates the date of conception by subtracting 266 days (38 weeks) from the known due date.
Discover When Conception Likely Occurred
Use our free tool to estimate conception based on birthdate or other key dates.
Estimate Your Conception Date Now! →How Does a Conception Calculator Based on Birthdate Work?
A typical pregnancy lasts around 40 weeks, or 280 days, from the first day of your last menstrual period (LMP). But what if you are looking to find your conception date from a birthdate? Then you'll need to leverage the dual functionality this tool provides:
- Enter the birthdate: Input the birthdate of the individual whose conception date you're curious about.
- The calculator subtracts: The Pregnancy Calculator & Ovulation Estimator then subtracts 266 days (38 weeks) from the known birth date (or due date).
- Estimated ovulation date: The resulting date is your estimated day of ovulation, because conception occurs soon after ovulation.
While pregnancies are said to last 40 weeks from the first day of your last menstrual period, we can simply subtract 38 weeks from the birthdate to estimate the conception date!
Other Factors Affecting the Accuracy
Keep in mind that this is an estimated date of conception. This method assumes that a pregnancy lasts 38 weeks from conception. Several factors can influence this calculation, including:
- Variations in cycle length:: A typical menstrual cycle is 28 days, but cycles vary.
- Ovulation Timing: Ovulation may not occur exactly mid-cycle.
- Premature birth:: If the baby was born before their due date, conception occurred more recently than the calculation reveals.
- Post-term birth: If the baby was born past their due date, the calculation would need to be adjusted to add more time to conception
What Else Can the Pregnancy Calculator & Ovulation Estimator Do?
- Determine your due date and current trimester
- Pinpoint your fertile window and ovulation day
- Track key pregnancy milestones
- Utilize an interactive six-month calendar color-coded with your period, fertile window, and ovulation day
This powerful tool offers personalized timelines and predictions to help you plan for conception or navigate pregnancy, all within an intuitive and responsive interface.
Try Our Ovulation Calculator
If you aren't currently pregnant and are trying to conceive, our ovulation calculator can help you pinpoint your most fertile days to help you get pregnant!