Pregnancy Week Calculator
Find your current week of pregnancy, trimester and due date from the first day of your last period.
Runs in your browser. Your files never leave your device. See how to check
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How to do it
- 1Fill in the boxes
Type your numbers or pick the options you need.
- 2See the result
The answer updates right away as you change a value.
- 3Use it
Copy the result or note it down. Nothing is sent anywhere.
About this tool
Enter the first day of your last menstrual period. The calculator shows how many weeks and days pregnant you are, the trimester, the expected due date (280 days from that date) and the days left. It is an estimate; an ultrasound can adjust the dates.
How pregnancy weeks are counted
Pregnancy is counted from the first day of the last menstrual period, so you are about two weeks pregnant at conception. A full term is about 40 weeks, or 280 days.
Trimesters
The first trimester ends at week 13, the second at week 27 and the third runs to birth.
Please note
This is for general information only and is not medical advice. Your doctor will confirm dates with a scan.
Tips for best results
Check every box before you rely on a result, because one wrong digit changes the whole answer. Use the exact figures from your payslip, bill, certificate or contract, and keep a note of the date you calculated. Rates, thresholds and rules change from time to time, so for tax, fees and legal matters treat the output as an estimate and confirm with the official source named on this page. You can run as many scenarios as you like; nothing is saved or sent, and refreshing the page clears the boxes.
Quick facts
- Category: Everyday Tools
- Works in your browser, no sign-up, no upload.
- Your input stays on your device.
- Available in English and Bangla.
- Content last reviewed:
Frequently asked questions
From which date is pregnancy counted?
From the first day of the last menstrual period.
Is the due date exact?
No. Only a small share of babies arrive on the due date.
What if my cycle is irregular?
Dates can be off. Ask your doctor for a scan-based date.
Is the date stored?
No.