First trimester
0-12 weeks
Pregnancy Due Date Calculator
Estimate due date, gestational week, delivery window, and milestones from LMP and cycle length for prenatal schedule planning
Calculation Inputs
Pregnancy Trimester Guide
Second trimester
13-27 weeks
Third trimester
After 28 weeks
This tool provides date estimation only and does not replace prenatal care or medical diagnosis.
Current Status
Enter LMP date and cycle length, and the tool will auto-calculate gestational age, due date, and milestone timeline.
Key Milestones
Enter LMP date and cycle length, and the tool will auto-calculate gestational age, due date, and milestone timeline.
Fetal Development Stage
Enter LMP date and cycle length, and the tool will auto-calculate gestational age, due date, and milestone timeline.
Prenatal Care Notes
Balanced nutrition and supplements
Take folate, iron, calcium, and other supplements based on professional advice instead of self-adjusting doses.
Regular routine and safe activity
Avoid prolonged sitting and high-risk intense workouts. Follow doctor-approved movement and exercise plans.
Attend prenatal visits
If abnormal bleeding, persistent abdominal pain, or water breaking occurs, seek medical care as soon as possible.
Documentation
What This Tool Does
The pregnancy due date calculator estimates due date, current gestational age, delivery window (plus or minus 7 days), and key milestone dates from the first day of the last menstrual period and cycle length.
Calculation Method
- Standard pregnancy length is estimated as 280 days (40 weeks).
- If cycle length is not 28 days, a day adjustment is applied as
cycle length - 28. - Due date = first day of LMP + adjusted pregnancy length.
- Estimated conception date is based on around day 14 with cycle adjustment.
How to Use
- Select the first day of your last menstrual period.
- Enter cycle length as an integer from 20 to 45 (default 28).
- Click
Calculate Due Date. - Review gestational week, progress, milestones, and stage guidance.
Result Fields
- Estimated Due Date: reference date for expected delivery.
- Estimated Conception Date: cycle-adjusted estimation.
- Delivery Window: date range from 7 days before to 7 days after due date.
- Time to Due Date: remaining or overdue days relative to today.
- Key Milestones: dates for week 12, 27, 37, and 40.
Typical Use Cases
- Pregnancy timeline and routine planning
- Prenatal visit scheduling
- Family preparation and task coordination
- Gestational progress tracking
Notes
- This tool is for date estimation and does not replace medical diagnosis.
- Irregular cycles, delayed ovulation, or special conditions may affect accuracy.
- Seek medical care promptly for abdominal pain, bleeding, water breaking, or other warning signs.