Pregnancy Due Date
Calculate expected delivery date
Pregnancy Due Date
Calculate your expected delivery date
Standard cycle is 28 days. Adjust if your cycle is longer or shorter.
Your Due Date
About Pregnancy Due Date Calculator
The Pregnancy Due Date Calculator helps expectant mothers estimate their baby's arrival date. Using Naegele's Rule (LMP + 280 days) or conception date + 266 days, our calculator provides a reliable due date estimate.
Track your pregnancy week by week, know which trimester you're in, and see how many days and weeks are left until your due date. Perfect for expecting parents planning for their baby's arrival.
How to Use This Pregnancy Due Date Calculator
Step 1: Select calculation method — LMP (Last Menstrual Period) or Conception Date.
Step 2: Enter the first day of your last period (LMP method) or conception date.
Step 3: (For LMP) Enter your average cycle length (standard is 28 days).
Step 4: Click "Calculate Due Date" to see your estimated delivery date.
Step 5: View due date, current week, days left, and trimester information.
Step 6: Use the Reset button to clear all inputs and start a new calculation.
Why Use a Pregnancy Due Date Calculator?
✓ Plan for Baby's Arrival
Know your estimated due date to plan maternity leave, baby nursery, hospital bags, and family support.
✓ Track Pregnancy Progress
Know which week and trimester you're in. Understand your baby's development milestones.
✓ Medical Appointment Planning
Schedule prenatal visits, ultrasounds, and important tests at the right gestational age.
✓ Multiple Methods
Calculate due date using LMP (Naegele's Rule) or conception date. Works for irregular cycles too.
How Due Date is Calculated
Naegele's Rule (LMP Method)
Due Date = LMP + 280 days (40 weeks)
Based on 28-day cycle with ovulation on day 14
Conception Method
Due Date = Conception + 266 days (38 weeks)
Use if you know exactly when you conceived
Pregnancy Trimesters
| Trimester | Weeks | Key Events |
|---|---|---|
| First Trimester | 1-12 weeks | Conception, heartbeat, organ formation |
| Second Trimester | 13-27 weeks | Movement felt, gender visible, growth spurt |
| Third Trimester | 28-40 weeks | Brain development, lung maturity, position for birth |
Pregnancy Week by Week Guide
Important Notes
- •Due date is an estimate — Only 5% of babies arrive exactly on their due date.
- •Full term is 39-40 weeks — Babies born at 37 weeks are early term, 41 weeks is late term.
- •Consult your doctor — This calculator provides estimates. Always follow your healthcare provider's advice.
Frequently Asked Questions
The most common method is Naegele's Rule: Add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14. Only about 5% of babies arrive exactly on their due date — most come between 37 and 42 weeks.
Due dates are estimates, not guarantees. Only 5% of babies arrive exactly on their due date. 80% arrive between 38 and 42 weeks. First-time moms often go past their due date. Ultrasounds in the first trimester are most accurate for dating pregnancy.
If your cycles are irregular, the LMP method may not be accurate. Your doctor will use an early ultrasound (around 8-12 weeks) to determine gestational age and due date. The first trimester ultrasound is the most reliable method.
LMP (Last Menstrual Period) is the first day of your last period. Conception usually happens about 14 days after LMP (around ovulation). Due date is calculated from LMP, not conception. If you know your conception date, add 266 days.
First trimester: Week 1-12 (early development). Second trimester: Week 13-27 (growth and movement). Third trimester: Week 28-40 (final development and preparation for birth). Each trimester has different milestones and symptoms.
Schedule your first prenatal visit around 8 weeks after your LMP. Earlier if you have medical conditions, previous complications, or are over 35. The first visit typically includes confirmation ultrasound, blood tests, and health history review.
Week 1-4: Fertilization and implantation. Week 5-8: Heartbeat begins, organs start forming. Week 9-12: Fingers, toes, facial features develop. Week 13-16: Baby can suck thumb, gender visible. Week 17-20: Movement felt (quickening). Week 21-24: Viability outside womb. Week 25-28: Brain rapidly developing, lungs maturing. Week 29-32: Growth spurt, baby turns head-down. Week 33-36: Baby gains weight, lungs fully mature. Week 37-40: Full term, ready for birth.
Gestational age: Measured from LMP (first day of last period) - this is what doctors use. Fetal age: Measured from actual conception date. Fetal age is 2 weeks less than gestational age. Example: 8 weeks gestational = 6 weeks fetal. Ultrasound dating uses gestational age.
First Trimester (Weeks 1-12): Morning sickness, fatigue, breast tenderness, frequent urination. Baby's organs forming, heartbeat by week 6. Second Trimester (Weeks 13-27): 'Honeymoon period' - less nausea, baby movement felt, gender visible. Third Trimester (Weeks 28-40): Back pain, swelling, Braxton Hicks, baby positions for birth, lungs maturing.
Schedule first prenatal visit at 8 weeks (from LMP). Earlier if: 1) High-risk pregnancy (35+ years, medical conditions), 2) Previous miscarriage, 3) IVF/IUI pregnancy, 4) Bleeding or severe pain. First visit includes: Ultrasound (confirm heartbeat/dates), Blood tests (blood type, anemia, infections), Blood pressure check, Urine test (protein, sugar).