Enter the first day of your last period to estimate your due date, your current week, and when each trimester begins. This is an estimate only. Your doctor may adjust your due date after an ultrasound.
How the Calculator Works
Doctors count pregnancy from the first day of your last period, not from conception. A full pregnancy is about 40 weeks (280 days). If your cycle is longer or shorter than 28 days, the date shifts a little, and this tool adjusts for that.
Want to know more? Read about pregnancy trimesters and full term pregnancy.
See our Medical Disclaimer. Always confirm your due date with your doctor or midwife.