Pregnancy Week Calculator

How to Use Pregnancy Week Calculator

1. Choose your input mode. Decide whether you know your LMP date or your estimated due date – toggle between the two.
2. Enter the relevant date. For LMP, pick the first day of your last period; for due date, provide the date your doctor gave you.
3. Click Calculate. The tool back‑calculates LMP from the due date if needed, then determines the exact week and day of pregnancy as of today.
4. Read your results. You’ll see your current week + day, trimester, a baby‑size comparison (e.g., “avocado” at 16 weeks), and how many weeks remain.

Benefits of Pregnancy Week Calculator

• Works with both LMP and due date, so you don’t have to remember the exact start of your cycle.
• Gives an instant, always‑up‑to‑date reading every time you open the tool – great for weekly check‑ins.
• The fruit‑size comparison makes the abstract week number more tangible and fun to follow.
• Runs entirely in your browser; no personal health data is uploaded or stored.

Frequently Asked Questions

Why does pregnancy week count from LMP when I wasn’t pregnant yet?

Obstetricians use LMP as a standard because ovulation date is often uncertain. It gives a consistent 40‑week reference, even though conception typically occurs two weeks later.

What if my ultrasound says a different due date?

Your provider may adjust the due date after an early ultrasound. If that happens, enter the updated due date into the calculator for the most accurate week tracking.

How accurate are the baby size comparisons?

They are approximate and based on average fetal measurements for each week. Actual size can vary, but the comparison gives a nice general idea of your baby’s growth.

Is Pregnancy Week Calculator free and private?

Yes — it is 100% free, needs no sign‑up, and everything runs in your browser; your data never leaves your device.