Due Date Calculator
Estimate pregnancy due date from your last menstrual period and see current pregnancy week.
Runs locally — nothing is uploaded
How to use
- 1
Enter your LMP date
Select the first day of your last menstrual period (LMP) using the date picker. This is the standard starting point for due date estimates.
- 2
View your estimated due date
The calculator adds 280 days (40 weeks) to your LMP and displays your estimated delivery date.
- 3
Check your current pregnancy week
See how many weeks and days pregnant you are today based on the time elapsed since your LMP.
- 4
Track days until due
Review how many days remain until your due date, or how many days past due you are if that date has already passed.
Frequently Asked Questions
This tool uses Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period. Most pregnancies deliver within two weeks of that date.
LMP-based estimates assume a regular 28-day cycle. An early ultrasound often gives a more precise due date, especially if your cycle length varies.
Pregnancy weeks are counted from the first day of your LMP, not from conception. Week 1 starts on that first day, so you are considered about two weeks pregnant at conception.
No. This is an educational estimate only. Always follow guidance from your obstetrician or midwife for prenatal care and delivery planning.
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