Pregnancy Calculator: The Complete Guide
Track your pregnancy from the first day of your last period. Enter that date to see how far along you are in weeks and days, your current trimester, your estimated due date, and how many days remain.
Who the Pregnancy Calculator is for
Expectant parents who want to know their current pregnancy week, trimester, and due date.
How to use the Pregnancy Calculator
- Type your values into the fields above — pick your currency or units where the calculator offers them.
- Results update automatically as you type; there's no submit button and nothing is sent to a server.
- Adjust any input to compare scenarios, then copy the result with a single click.
How it works
Gestational age is counted from the first day of your last menstrual period (LMP). The due date is LMP + 280 days (40 weeks), and the trimester follows from the week count.
Features
- Current week & day
- Trimester
- Estimated due date
- Days remaining
How pregnancy is dated
Pregnancy is conventionally dated from the first day of your last period — about two weeks before conception — which is why 40 weeks is full term even though gestation is around 38 weeks. An early dating ultrasound can refine this, and your provider's date should take precedence over any calculator estimate.