When Is My Baby Coming Calculator
'/%3E%3Ccircle cx='48' cy='39' r='19' fill='%23f2c9a5'/%3E%3Cpath d='M27 35c3-16 39-17 42 2-8-8-27-9-42-2z' fill='%23374151'/%3E%3Cpath d='M21 86c5-24 49-28 56 0z' fill='%232563eb'/%3E%3Ccircle cx='41' cy='41' r='2' fill='%23111827'/%3E%3Ccircle cx='55' cy='41' r='2' fill='%23111827'/%3E%3Cpath d='M42 52c4 3 9 3 13 0' stroke='%2392400e' stroke-width='3' fill='none' stroke-linecap='round'/%3E%3C/svg%3E)
Reviewed by Calculator Editorial Team
Pregnancy due dates are estimated based on the first day of your last menstrual period (LMP) or ultrasound date. This calculator provides an estimated due date and tracks your pregnancy week by week.
How to Use This Calculator
To estimate your due date:
- Enter the date of your last menstrual period (LMP) or ultrasound date
- Select whether you're using LMP or ultrasound date
- Click "Calculate" to see your estimated due date
- Track your pregnancy week by week using the chart
The calculator uses standard pregnancy duration of 40 weeks (280 days) from conception. Keep in mind that due dates are estimates and actual delivery dates may vary.
How Pregnancy Due Dates Are Calculated
There are two primary methods for calculating due dates:
Last Menstrual Period (LMP) Method
The most common method adds 280 days (40 weeks) to the first day of your last menstrual period. This is based on the average length of pregnancy.
Formula: Due Date = LMP Date + 280 days
Ultrasound Date Method
When you have an ultrasound, the doctor measures the gestational sac and calculates the due date based on the estimated conception date.
Formula: Due Date = Ultrasound Date + (280 days - (weeks × 7 days))
Note: Due dates are estimates. Actual delivery dates can vary by several days or weeks. Always consult with your healthcare provider for personalized advice.
Example Calculation
Let's say your last menstrual period started on January 1, 2023. Using the LMP method:
- Start with January 1, 2023
- Add 280 days (40 weeks)
- Result: October 29, 2023
This means your estimated due date would be October 29, 2023.
Frequently Asked Questions
How accurate are pregnancy due dates?
Due dates are estimates based on average pregnancy lengths. Actual delivery dates can vary by several days or weeks. Always consult with your healthcare provider for personalized advice.
Can I use this calculator if I had an ultrasound?
Yes, you can use the ultrasound date method by selecting "Ultrasound Date" and entering the date from your ultrasound. The calculator will adjust the due date based on your specific ultrasound findings.
What if I miss my period?
If you're unsure about your last menstrual period, you can estimate based on your cycle length or use the ultrasound date method if you've had one.
How do I track my pregnancy week by week?
The calculator shows your current pregnancy week based on today's date. You can use the chart to track your progress throughout your pregnancy.