Health
Pregnancy Due Date Calculator
Calculate your estimated due date, find out how many weeks pregnant you are, and track which trimester you're in. Enter the first day of your last menstrual period (LMP) for instant results.
Pregnancy Trimester Guide
First TrimesterWeeks 1–12
Major organ development, morning sickness common, highest miscarriage risk. Avoid alcohol, smoking, raw fish, and certain medications.
Second TrimesterWeeks 13–26
Often the most comfortable trimester. Baby bump visible, movement felt around week 18–22. Anatomy scan at week 20. Energy typically improves.
Third TrimesterWeeks 27–40
Baby gains most weight. Braxton Hicks contractions begin. Baby's position matters. Prepare hospital bag and birth plan. Watch for signs of labor.
Ad Space — 90px
Frequently Asked Questions
How is my due date calculated?
Your estimated due date (EDD) is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). This is known as Naegele's rule. It assumes a 28-day cycle and ovulation on day 14. For cycles significantly shorter or longer than 28 days, your doctor may adjust the estimate using ultrasound measurements.
How many weeks pregnant am I?
Pregnancy is counted from the first day of your last menstrual period, not from conception. So even before you conceived, you were already considered 2 weeks pregnant by medical counting. Enter your LMP date above and the calculator will tell you exactly how many weeks and days pregnant you are today.
What are the three trimesters of pregnancy?
The first trimester runs from week 1 through week 12 — this is when the baby's major organs form and miscarriage risk is highest. The second trimester covers weeks 13–26 — often the most comfortable period, when the baby bump becomes visible and movement is felt. The third trimester spans weeks 27–40 — the final stretch where the baby gains most of its weight and prepares for birth.
How accurate is the due date calculator?
This calculator gives an estimated due date based on your LMP and a standard 28-day cycle. Only about 4–5% of babies are born on their exact due date. Most births occur within 2 weeks before or after. Your healthcare provider may adjust the date based on a first-trimester ultrasound, which is considered the most accurate dating method.
When does a baby become viable?
Medical viability — the point at which a premature baby can potentially survive outside the womb with intensive care — is generally considered to be around 24 weeks of gestation. Survival rates improve significantly with each additional week. At 24 weeks: ~50% survival. At 28 weeks: ~90%. At 32 weeks: ~99%. Full term is 37–42 weeks.
What is the conception date?
Conception typically occurs around 14 days after the start of your last period, when ovulation happens in a standard 28-day cycle. This calculator estimates your conception date by adding 14 days to your LMP. However, sperm can survive up to 5 days inside the body, so the actual conception window is approximately days 10–16 of your cycle.
What prenatal tests should I expect by trimester?
First trimester (weeks 8–13): blood tests, nuchal translucency ultrasound, genetic screening. Second trimester (weeks 15–20): quad screen blood test, anatomy scan ultrasound around week 20. Third trimester (weeks 28–36): glucose tolerance test for gestational diabetes, Group B strep test, regular cervical checks. Always follow your OB's or midwife's specific recommendations.