Pregnancy Week Calculator

Skycally's Pregnancy Week Calculator tells you exactly how many weeks and days pregnant you are, estimates your due date, and shows you what is happening with your baby right now — all from a single date. Enter the first day of your last menstrual period (or your known due date or conception date) and the calculator instantly gives you your gestational age, trimester, days remaining, and a percentage-complete progress bar. No account required, no personal data stored.

Each week of pregnancy brings remarkable changes. The week-by-week development guide describes what is happening with your baby — from the neural tube forming at week 4 to the lungs developing surfactant at week 24 to the baby settling into a head-down position at week 32. Alongside each developmental update, the guide notes what physical changes you might experience and includes a practical tip for that specific stage. The baby size card compares your baby's current size to a familiar fruit or vegetable — from a poppy seed at week 4 to a pumpkin at week 40.

The trimester timeline provides a visual overview of your entire pregnancy journey, showing exactly where you are within the three trimesters and marking the key clinical milestones: first heartbeat detectable at week 6, anatomy scan window at weeks 18-22, viability milestone at week 24, and full term at week 39. The key dates card translates these milestones into actual calendar dates based on your specific due date, so you know exactly when each appointment window falls.

Pregnancy nutrition and hydration are critical throughout all three trimesters. Use our Water Intake Calculator to set a precise daily fluid target — pregnant women typically need 300ml more per day than usual. Our Sleep Calculator can help you optimise rest during pregnancy, when quality sleep becomes increasingly important. For nutritional planning, the Calorie Calculator can estimate the additional calories needed during each trimester.