40 weeks pregnant in months
By Pregora Editorial Team · Updated 2026-04-26 · 3 min read
If you are 40 weeks pregnant, you are approximately 9 months. The conversion isn't always perfectly clean because pregnancy lasts 40 weeks but the calendar uses 12 months — the standard medical convention is 4.345 weeks per month. Here's everything you need to know about week 40.
Quick answer
9 months
40 weeks pregnant. You are in the third trimester (weeks 27–40).
What's happening at 40 weeks pregnant
Past due date. Most providers discuss induction around week 41. Baby is fully cooked.
How weeks-to-months conversion works
Pregnancy is counted in weeks, not months, because weeks are more precise. To convert: divide the week count by ~4.345 (the average weeks per month over a 9-month, 40-week pregnancy). For week 40: 40 ÷ 4.345 ≈ 9 months and 0 extra days.
Trimester at week 40
Week 40 falls in the Third trimester (weeks 27–40). The third trimester is when baby gains weight rapidly, prenatal visits become weekly, and labour preparation begins.
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Medical disclaimer: This article is for general information only. Always consult your healthcare provider about your individual pregnancy.
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