🌸 Pregnancy Week Calculator
Select your calculation method and enter the date below
⚠️ Please choose a valid date using the selectors or calendar.
🩺 This calculator is for informational purposes only. Always consult your healthcare provider for medical guidance during pregnancy.
Your Pregnancy Results
Based on your input
Current Week
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Current Trimester
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Estimated Due Date
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Full-term delivery
Calculation Method
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Total Pregnancy Days
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From conception to EDD
Days Remaining
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Approximate Month of Pregnancy
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Pregnancy Progress
0%
Week 1
Start
Start
Week 12
1st Trimester
1st Trimester
Week 27
2nd Trimester
2nd Trimester
Week 40
Due Date
Due Date
About This Tool
How the Pregnancy Week Calculator Works
Knowing exactly how far along you are is one of the most important and exciting parts of pregnancy. Our free Pregnancy Week Calculator gives you instant, accurate results based on the information you have — whether that's the start of your last period, your ultrasound report, your estimated due date, or your IVF embryo transfer date.
The calculator works by determining the gestational age — the number of weeks and days that have passed since the beginning of your pregnancy — and then mapping that to your trimester, due date, and days remaining.
All five calculation methods (LMP, EDD, Ultrasound, Conception, and Embryo Transfer) are medically recognised. The result displayed reflects today's date relative to your pregnancy timeline, giving you real-time accuracy every time you use it.
Last Menstrual Period (LMP)
The most widely used method for regular cycles. Due date = LMP + 280 days, then adjusted by your selected cycle length minus 28 days.
Estimated Due Date (EDD)
Already know your due date? We calculate backwards from your EDD to find your current week and LMP equivalent.
Gestational Age by Ultrasound
Most accurate in the first trimester. Enter your scan date and the gestational age shown on your report. We recalculate from there.
Date of Conception
Know the day you conceived or ovulated? Conception adds approximately 14 days to get the LMP-equivalent for calculation.
Embryo Transfer Date (IVF/FET)
For IVF pregnancies. Day-3 transfers add 17 days; Day-5 blastocyst transfers add 19 days to calculate your gestational LMP equivalent.
Your Journey
The Three Trimesters of Pregnancy
Each trimester brings incredible growth and milestones for you and your baby.
First Trimester
Weeks 1 – 12
The foundation of life. Major organs begin forming and the embryo becomes a fetus by week 10.
- Heart starts beating (week 6)
- Brain and spinal cord forming
- Limb buds appear (week 7–8)
- Risk of miscarriage decreases after week 12
- First prenatal visit recommended
Second Trimester
Weeks 13 – 27
The golden trimester. Nausea often eases and you may feel baby's first movements (quickening).
- Gender may be determined (week 18–20)
- Baby begins hearing sounds
- Anatomy scan ultrasound
- Baby's movements felt (week 16–22)
- Skin, hair, and nails develop
Third Trimester
Weeks 28 – 40
The final stretch. Rapid weight gain, brain development, and preparation for birth.
- Baby gains significant weight
- Lungs mature (week 34–36)
- Baby moves into head-down position
- Group B Strep test (week 35–37)
- Full-term at 39 weeks 🎉
Common Questions
Frequently Asked Questions
How many weeks is a full-term pregnancy?
A full-term pregnancy lasts 40 weeks (280 days) from the first day of your last menstrual period (LMP). Babies born between 39–40 weeks 6 days are considered full-term.
What is LMP in pregnancy?
LMP stands for Last Menstrual Period. It's the most common dating method. Your due date is calculated as 40 weeks (280 days) from the first day of your LMP, using Naegele's Rule.
How accurate is the pregnancy week calculator?
This calculator gives an estimate based on the method you choose. Ultrasound-based dating, especially in the first trimester, is the most clinically accurate. LMP calculations are most reliable when your cycle is regular, and cycle-length adjustments are estimates.
When does the second trimester start?
The second trimester begins at week 13 and runs through week 27. It's often considered the most comfortable stage, as early pregnancy symptoms typically ease during this period.
How is IVF pregnancy dating different?
For IVF pregnancies, the gestational age is counted from a calculated LMP equivalent. For Day-3 embryo transfers, we add 17 days; for Day-5 blastocyst transfers, we add 19 days to get the equivalent LMP date.
What if I don't remember my LMP date?
No worries! Use the EDD method if your doctor has given you a due date, or the Ultrasound method if you have a scan report with gestational age. Both give equally accurate results.
What does gestational age mean?
Gestational age is the age of the pregnancy measured from the first day of the last menstrual period — not from conception. That's why pregnancies are "40 weeks" long even though fertilisation happens around week 2.
Can I use this calculator for twins?
Yes! The weekly calculations are the same for twin pregnancies. However, the expected delivery for twins is typically around 36–38 weeks rather than 40 weeks. Always follow your OB's guidance for multiple pregnancies.