Pregnancy Calculator
Track your pregnancy week by week. Get due date, trimester info, baby size estimates, and important milestones.
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About the Pregnancy Calculator
This calculator gives you a complete picture of your pregnancy timeline: your estimated due date, how many weeks and days along you are, which trimester you are in, and key milestones along the way. It is a friendly companion for following the journey week by week, built on the standard dating method using your last menstrual period.
Pregnancy is full of milestones, and having them mapped out can make the experience feel more grounded and exciting. I will explain how the timeline works and what the trimesters mean, while always pointing back to your prenatal care team as the real guides through it all.
How the timeline is calculated
Pregnancy is dated from the first day of your last menstrual period and runs about 40 weeks to the estimated due date. From your last period, the calculator works out your current gestational age (in weeks and days) and projects the milestones ahead. Because dating starts from the last period rather than conception, you are considered about two weeks pregnant by the time conception actually occurs, which surprises many people.
The three trimesters
Pregnancy is divided into three trimesters. The first (roughly weeks 1 to 13) is when the baby's major structures form and early symptoms like fatigue and nausea are common. The second (about weeks 14 to 27) is often the most comfortable stretch, when many people feel their best and start to feel movement. The third (weeks 28 to birth) is the growth and preparation phase leading up to delivery. The calculator shows which one you are in.
Milestones to look forward to
Along the way come meaningful moments: the first prenatal appointment and early ultrasound, hearing the heartbeat, the anatomy scan around the midpoint, feeling those first kicks, and the point of viability later on. These are general markers, and every pregnancy unfolds a little differently. Seeing them laid out can help you anticipate appointments and savor the journey, while your provider confirms the specifics for you.
Your care team comes first
This calculator is a lovely way to follow your progress, but it does not replace prenatal care. Regular appointments are how your pregnancy is properly monitored, your dates confirmed, and any questions answered. Use the timeline to stay oriented and engaged, and lean on your doctor or midwife for guidance, reassurance and the personalized care that makes all the difference.
Sources & method
This calculator uses established, peer-reviewed formulas and reference ranges from recognized health and nutrition authorities. Results are estimates for general education, not a medical diagnosis. For decisions about your health, consult a qualified clinician. Reviewed by Macro & Meals Editorial Team, Content editor.
Frequently Asked Questions
The calculator works out your gestational age in weeks and days from the first day of your last menstrual period. Because dating starts from the last period rather than conception, you are considered about two weeks pregnant by the time conception actually occurs.
The first trimester is roughly weeks 1 to 13, when the baby's major structures form; the second is about weeks 14 to 27, often the most comfortable stretch; and the third is weeks 28 to birth, the growth and preparation phase. The calculator shows which trimester you are in.
Pregnancy lasts about 40 weeks from the first day of your last menstrual period to the estimated due date. Babies born from 37 weeks are considered term, and arriving a week or two on either side of the due date is entirely normal.
No. It is a friendly way to follow your timeline and milestones, but regular prenatal appointments are how your pregnancy is properly monitored and your dates confirmed. Always rely on your doctor or midwife for guidance, reassurance and personalized care.
