TeeNee Calculator
Pregnancy tools for expecting parents

Pregnancy Week & Month Chart

Select a week to see the pregnancy month, trimester, approximate length, weight, size, and development from weeks 1-42.

Explore week-by-week growth

Enter gestational age

See the pregnancy month, trimester, percentage completed, and approximate size.

Loading the weekly chart...

Pregnancy months and weeks

The same ranges are used throughout these tools: week 8 is in month 2, and week 40 is in month 9.

MonthWeek rangeTrimester

Approximate baby size by week

Each week includes an illustration, approximate length, weight, and size comparison to make changes easier to follow.

ImageWeekMonthLengthWeightSize comparison
Showing 4 of 42 weeks
Important note

All results are estimates intended to provide a helpful overview. They do not replace an ultrasound, diagnosis, or medical advice. Length is shown around a weekly reference value. Weight ranges from week 22 use the 10th-90th percentiles from the INTERGROWTH-21st standard.

Pregnancy tools in this series

Move easily from cycle tracking to ovulation, gestational age, due date, conception date, and a week-by-week chart.

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