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Pregnancy Weeks to Months Converter
Easily convert pregnancy weeks into months and trimesters with our comprehensive chart.
Quick Week Lookup
Complete Pregnancy Weeks to Months Chart
| Weeks | Month | Trimester | Key Development |
|---|---|---|---|
| Weeks 1-4 | Month 1 | First Trimester | Fertilisation and implantation. The embryo is tiny but cells are multiplying rapidly. |
| Weeks 5-8 | Month 2 | First Trimester | Heart begins to beat. Arm and leg buds form. Brain development accelerates. |
| Weeks 9-13 | Month 3 | First Trimester | All major organs are formed. Fingers and toes develop. Baby starts moving. |
| Weeks 14-17 | Month 4 | Second Trimester | Baby can make facial expressions. Gender may be visible on ultrasound. |
| Weeks 18-22 | Month 5 | Second Trimester | Baby can hear sounds. You may start feeling movements (quickening). |
| Weeks 23-27 | Month 6 | Second Trimester | Lungs developing. Baby responds to light and sound. Regular sleep cycles begin. |
| Weeks 28-31 | Month 7 | Third Trimester | Baby opens eyes. Rapid brain development. Can recognise your voice. |
| Weeks 32-35 | Month 8 | Third Trimester | Baby gains weight quickly. Lungs are maturing. Head-down position is common. |
| Weeks 36-40 | Month 9 | Third Trimester | Baby is full-term. Lungs are mature. Ready for birth at any time. |
First Trimester
Weeks 1-13 (Months 1-3)
Foundation period. All major organs form. Morning sickness, fatigue, and breast changes are common. Highest risk of miscarriage in this phase.
Second Trimester
Weeks 14-27 (Months 4-6)
Often called the "golden trimester." Energy returns, baby bump shows. You will feel baby movements and have the anatomy scan.
Third Trimester
Weeks 28-40 (Months 7-9)
Final stretch. Baby gains weight rapidly. Back pain, frequent urination, and Braxton Hicks contractions are common. Prepare for delivery.
Medical Disclaimer
- This chart provides general guidance. Every pregnancy is unique.
- Month boundaries are approximate since calendar months vary in length.
- Consult your doctor for personalised pregnancy milestones and check-up schedules.
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