Pregnancy Week Calculator
See your trimester, baby size comparison, and countdown by pregnancy week.
Last updated: June 13, 2026
Calculator
Results
Week 16
How to Use This Calculator
- 1Enter your current number of weeks pregnant.
- 2Add extra days (0-6) if known.
- 3View your trimester, pregnancy month, and baby size comparison.
- 4Track your countdown to your due date.
Formula Explanation
Pregnancy is divided into three trimesters spanning approximately 40 weeks (280 days). Each week, the baby grows significantly and is often compared to common fruits and vegetables for easy reference.
Variables:
Worked Examples
16 weeks pregnant
- 1. Trimester: 2nd (weeks 13-26)
- 2. Month: ~4
- 3. Baby size: Avocado (~4.6 inches)
- 4. Days remaining: 280 - 112 = 168
32 weeks 3 days pregnant
- 1. Trimester: 3rd (weeks 27-40)
- 2. Month: ~8
- 3. Baby size: Squash (~16.7 inches)
- 4. Days remaining: 280 - 227 = 53
Why Use This Calculator
- Fun baby size comparisons every week — from poppy seed to pumpkin.
- Instant trimester and month identification.
- Countdown to your due date in days and weeks.
- Share your weekly milestone with family and friends.
Tips & Best Practices
- Baby size comparisons are approximate averages — every baby grows at their own rate.
- The second trimester (weeks 13-26) is often called the "golden period" with more energy and less nausea.
- Start feeling baby movements (quickening) around weeks 16-22.
- Third trimester is when the most weight gain occurs for both mom and baby.
Common Mistakes to Avoid
❌ Thinking months and weeks align perfectly.
✅ Pregnancy months don't align exactly with calendar months. 40 weeks is closer to 9 months and 1 week, not exactly 9 months.
❌ Worrying about exact size measurements.
✅ Size comparisons are averages. Your baby may be smaller or larger than the comparison and still be perfectly healthy.
Frequently Asked Questions
How many months is 20 weeks pregnant?
What size is my baby at 12 weeks?
When does each trimester start and end?
Embed This Calculator
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<iframe src="https://redicalc.com/embed/health/pregnancy-week-calculator" width="100%" height="600" style="border:none;border-radius:12px;box-shadow:0 1px 3px rgba(0,0,0,0.1);" title="Pregnancy Week Calculator — RediCalc.com" loading="lazy" allowtransparency="true"></iframe>Disclaimer: This calculator is provided for informational and educational purposes only. Results are estimates and should not be used as a substitute for professional advice. RediCalc.com makes no guarantees regarding the accuracy, completeness, or suitability of any calculations. Always consult a qualified professional before making financial, health, construction, or other important decisions.
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