Calculator
How many weeks pregnant am I?
Enter the first day of your last period and we'll estimate how many weeks pregnant you are and your due date. Private, free, and no sign-up.
How the calculator works
Pregnancy is counted from the first day of your last menstrual period (LMP), not from the day of conception — that's the standard way doctors date a pregnancy. So on the day your period was due, you're already counted as about 4 weeks pregnant. This calculator takes the number of days since your last period and converts it to weeks and days.
Why an ultrasound is the most accurate
Dating from your last period assumes a regular 28-day cycle. If your cycles are irregular, or you're not sure of the date, the estimate can be off by a week or two. An early ultrasound measures the pregnancy directly and gives the most accurate dating. A counsellor can help you arrange one.
What the weeks mean for your options in Thailand
Abortion is legal in Thailand on request up to 12 weeks of pregnancy, and from 12 to 20 weeks after counselling. Residency is not required — you can travel here for care. Knowing roughly how far along you are helps you understand which options are open to you and how quickly to act.
Questions people ask
How do I count how many weeks pregnant I am?
Count from the first day of your last period, not from conception. This calculator does it for you — just enter that date.
Is the calculator accurate?
It's a good estimate based on your last period. If your cycle is irregular or you're unsure of the date, an ultrasound is more accurate.
Is this private?
Yes. The calculation happens on your device and nothing is saved unless you choose to start a chat. You can also leave the site instantly at any time.
What if I'm past 12 or 20 weeks?
Options become more limited as the weeks go on, so it's best to talk to a counsellor as soon as you can — they'll help you understand what's still possible.