Pregnancy Due Date Calculator

First day of your last period

Average cycle length (days)

Estimated due date

Estimated conception date: -

Current pregnancy week

Weeks remaining: -

Trimester timeline

Current trimester: -
First trimester ends: -
Second trimester ends: -
Third trimester starts: -

👶 Pregnancy Journey:

Every pregnancy is unique! Track your milestones, attend regular checkups, and join prenatal classes. Use our Ovulation Calculator if planning another pregnancy in the future.

Understanding Due Date Calculations

Due date calculations are estimates based on standard pregnancy length of 280 days (40 weeks) from the first day of your last menstrual period. This calculator uses the Naegele's Rule, which is the most common method used by healthcare providers worldwide.

Calculation Methods Explained

Method	Calculation	Accuracy
LMP (Last Menstrual Period)	LMP + 280 days (adjusted for cycle length)	Good for regular cycles
First Trimester Ultrasound	Based on fetal measurements (CRL)	Most accurate (±5-7 days)
Conception Date	Conception date + 266 days	Good if date is known
IVF Transfer	Transfer + 263 days (Day 3) or 261 days (Day 5)	Very accurate

Important Facts About Due Dates

Only 5% of babies arrive on their due date - Most babies are born within 2 weeks before or after the estimated date.
First babies often arrive later - First-time mothers tend to deliver slightly past their due date.
Irregular cycles need adjustment - If your cycle is shorter or longer than 28 days, adjust the cycle length for more accurate results.
Early ultrasound is most accurate - Ultrasound in first trimester (8-12 weeks) provides the most reliable due date estimate.
Full term is 37-42 weeks - Babies born between 37-42 weeks are considered full term and healthy.

When to Seek Medical Advice

No fetal movement for several hours after 28 weeks
Vaginal bleeding or severe cramping
Severe headache, vision changes, or upper abdominal pain
Contractions before 37 weeks
Water breaks (fluid leakage)

Family Planning Tools: Ovulation & Fertility Calculator • Age Calculator

⚠️ IMPORTANT: This calculator provides estimates only. Only 5% of babies arrive on their exact due date. Always confirm your due date with a qualified healthcare provider and attend all prenatal appointments. This tool should NOT be used for contraception or medical diagnosis.