ganak.appPregnancy Due Date Calculator
Free pregnancy due date calculator to estimate when your baby will arrive. Calculate your estimated due date using last menstrual period (LMP), conception date, IVF transfer date, or ultrasound. Includes gestational age, trimester timeline, pregnancy milestones, and week-by-week progress tracker. Uses Naegele's Rule with cycle-length adjustment. Supports irregular cycles (20-45 days).
The date your most recent period started
28 days is the average. Leave as-is if unsure.
Trimester Timeline
Your pregnancy divided into three trimesters
Pregnancy Milestones
Key dates and developmental markers throughout your pregnancy
Key Dates
Important dates based on your last menstrual period (naegele's rule) calculation
All dates are estimates. Only about 4–5% of babies are born on their exact due date. Most births occur between 37 and 42 weeks of gestation.
How Is Your Pregnancy Due Date Calculated?
Understanding the methods behind due date estimation
A pregnancy due date (also called the estimated date of delivery or EDD) predicts when your baby will arrive. Most pregnancies last about 280 days (40 weeks) from the first day of the last menstrual period (LMP). Our calculator supports four medically recognized methods:
1. Last Menstrual Period (LMP) — Naegele's Rule
The most common method. Add 280 days to the first day of your last period. If your cycle is not 28 days, the calculator adjusts automatically. Formula: EDD = LMP + 280 + (cycle length − 28). This is the standard method used by obstetricians for initial dating.
2. Conception Date
If you know when conception occurred (for example, through ovulation tracking), this method adds 266 days (38 weeks) to that date. This is more precise because it skips the variable follicular phase of the menstrual cycle.
3. IVF Transfer Date
For IVF pregnancies, the embryo age at transfer is known precisely. A Day 5 (blastocyst) transfer adds 261 days; a Day 3 transfer adds 263 days. This is the most accurate method for IVF pregnancies.
4. Ultrasound Dating
An early ultrasound (before 12 weeks) measures the embryo and reports a gestational age. The calculator uses this to back-calculate the LMP and project the due date. First-trimester ultrasounds are accurate to within ±5–7 days.
Important: Only about 4–5% of babies are born on their exact due date. The EDD is the midpoint of a normal delivery range — most babies arrive between 37 weeks (early term) and 42 weeks (post-term). Your healthcare provider may adjust your due date based on early ultrasound findings.
Pregnancy Trimester Guide
What to expect during each stage of pregnancy
First Trimester (Weeks 1–12)
Major organ systems form. Common symptoms include nausea (morning sickness), fatigue, breast tenderness, and frequent urination. The baby's heartbeat is detectable by week 6. By week 12, all major organs have started developing and the risk of miscarriage drops significantly.
Second Trimester (Weeks 13–26)
Often called the “golden trimester” as nausea typically subsides. You may start feeling baby movements (quickening) around weeks 16–20. The anatomy scan at week 20 checks development and can reveal the baby's sex. The baby grows rapidly and begins developing fingerprints and a regular sleep cycle.
Third Trimester (Weeks 27–40)
The baby gains weight rapidly, and the lungs mature. You may experience back pain, Braxton Hicks contractions, and increased fatigue. The baby reaches viability at week 24 and is considered full-term at week 39. The baby typically moves into a head-down position by week 36 in preparation for birth.
How Accurate Is a Pregnancy Due Date?
Limitations and factors that can affect your due date
Due date calculators provide an estimate, not a guarantee. Several factors affect accuracy:
When to see your doctor: If you are unsure about your last period date, if there is a discrepancy of more than 7 days between your LMP-based and ultrasound-based due dates, or if you have any concerns about your pregnancy.
Frequently Asked Questions
Common questions about pregnancy due dates, gestational age, and calculation methods