Gestational Age Calculator
Calculate gestational age from the first day of your last menstrual period (LMP). Track your pregnancy week by week and see your trimester progress.
First Trimester
What is Gestational Age?
Gestational age is the measure of how far along a pregnancy is, typically calculated from the first day of the last menstrual period (LMP) to the current date. A full-term pregnancy is approximately 40 weeks (280 days).
Pregnancy is divided into three trimesters: the first trimester (weeks 1-12), second trimester (weeks 13-28), and third trimester (weeks 29-40). Each trimester brings different developmental milestones for the baby and different experiences for the mother.
Our gestational age calculator uses your LMP date to calculate the current gestational age in weeks and days, shows your progress bar toward 40 weeks, and tells you which trimester you're in. Ultrasound measurements can also be used to confirm gestational age, especially in early pregnancy.