Find your baby's due date and see how your little one is growing.
The standard estimate adds 280 days (40 weeks) to the first day of your last menstrual period. Early ultrasound can refine the estimate during clinical care.
EDD = LMP + 280 days — adjusted by cycle length when your cycle isn't 28 days.
It is a planning estimate based on Naegele's rule (LMP plus 280 days). A clinician may revise the date using early ultrasound, which is the most accurate dating method.
The standard formula assumes a 28-day cycle. If yours is longer or shorter, the actual due date can shift by several days. Speak with your provider for a personalized estimate.
Yes — add 266 days to the conception date as an alternate formula. This is useful if you know the exact ovulation or conception day.
ACOG and the CDC recommend a daily prenatal vitamin with at least 400 micrograms of folic acid before pregnancy and 600 mcg total during pregnancy, plus 27 mg of iron daily. Folic acid helps prevent neural tube defects. Discuss specific brands and dosing with your provider, especially if you have a history of NTDs.
ACOG recommends about 150 minutes per week of moderate aerobic activity in an uncomplicated pregnancy. Walking, swimming, stationary cycling, low-impact aerobics, and modified yoga or Pilates are generally safe. Avoid contact sports, scuba diving, hot yoga, and activities with a high fall risk such as off-road cycling or horseback riding. After the first trimester, avoid lying flat on your back.
Pelvic floor exercises (Kegels), deep supported squats, child's pose, cat-cow stretches, and side-lying hip openers are commonly recommended to mobilize the pelvis and lengthen the pelvic floor. Practicing slow diaphragmatic breathing is also useful. Always clear any new routine with your provider, particularly in the third trimester.
Avoid raw or undercooked meat, eggs, and seafood; deli meats unless heated to steaming (165°F); high-mercury fish (shark, swordfish, king mackerel, tilefish, bigeye tuna); soft cheeses made from unpasteurized milk (some brie, feta, queso fresco); raw sprouts; unpasteurized juice and milk; and refrigerated pâtés. Limit caffeine to under 200 mg per day. There is no safe level of alcohol during pregnancy.
Missed period, nausea or vomiting (often called morning sickness, can occur any time of day), breast tenderness, fatigue, frequent urination, food aversions or cravings, mild cramping, and mood changes are typical. Symptoms usually peak around weeks 7–9 and ease by the end of the first trimester. Light spotting can be normal but should be reported to your provider.
Call right away (or seek emergency care) for: heavy vaginal bleeding, severe abdominal or pelvic pain, persistent vomiting that prevents keeping fluids down, fever over 100.4°F, severe headache that won't resolve, vision changes, sudden swelling of the face or hands, chest pain or trouble breathing, leg pain or swelling, leaking fluid from the vagina before 37 weeks, decreased fetal movement after about 28 weeks, or thoughts of harming yourself or your baby. When unsure, contact your provider — these calls are expected.
ACOG recommends side sleeping during the second and third trimesters. Either side is fine; left-side sleeping may slightly improve circulation. Lying flat on your back after about 20 weeks can compress a major vein (the inferior vena cava) and reduce blood flow. Bend a knee or two and use pillows between knees, under the belly, or behind the back for support.
ACOG recommends 8 to 12 cups (64–96 ounces) of fluid per day during pregnancy, more if you are active or in hot weather. Adequate hydration supports increased blood volume, amniotic fluid, and waste removal. Pale yellow urine is a quick check for good hydration. Limit caffeine and avoid sugary drinks.
Chorionic Villus Sampling (CVS) is a prenatal diagnostic test that examines a small sample of placental tissue (chorionic villi) to check for chromosomal conditions such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), and many inherited single-gene disorders. It is typically performed between 10 and 13 weeks of pregnancy, earlier than amniocentesis.
CVS is an invasive procedure and carries a small risk of miscarriage (commonly cited around 0.2%). It does not test for neural tube defects, which require separate screening. The choice between CVS, amniocentesis, and non-invasive prenatal testing (NIPT) depends on your individual risk profile, gestational age, and goals.
This information is educational only and is not medical advice. Discuss prenatal testing options with a qualified obstetrician or genetic counselor.
This calculator provides general estimates only and is not medical advice.
Estimate your expected due date from your last menstrual period or conception date; track pregnancy weeks and trimesters; plan prenatal appointments.
Enter the first day of your last menstrual period. The calculator estimates your due date, current pregnancy week, and trimester — useful for planning your first prenatal visit.
The standard method adds 280 days (40 weeks) from the first day of your last menstrual period. This is called Naegele's rule and is the basis used by most healthcare providers.
It is an estimate. Only about 5% of babies are born on the predicted due date. Your provider may adjust the estimate based on ultrasound measurements.
Enter your conception date if known — the calculator adjusts the 280-day window accordingly and recalculates the estimated due date.
The standard calculation assumes a 28-day cycle. If your cycle is significantly shorter or longer, discuss adjustment with your OB or midwife for a more accurate estimate.
The first trimester runs through week 12, the second from week 13 to 26, and the third from week 27 until delivery. The calculator shows your current trimester based on your entered date.
A home pregnancy test typically turns positive around 10–14 days after conception, which is roughly 3.5–4 weeks into a standard 40-week pregnancy timeline. If you know the approximate date of your positive test, count back 10–14 days to estimate conception, then add 266 days — or simply enter your last menstrual period date if known, which is the more standard method.
Gestational age is measured from the first day of your last menstrual period (LMP) — the clinical standard. Fetal age (or embryonic age) counts from conception, which is approximately 2 weeks after LMP. When your provider says "you're 8 weeks," they mean 8 weeks gestational age; the embryo is approximately 6 weeks old. All due date calculators use gestational age.
Most providers schedule a dating ultrasound between 8 and 12 weeks, when fetal size measurements are most accurate for confirming or adjusting the due date. A transvaginal ultrasound can detect a heartbeat as early as 6 weeks. If your LMP-based due date differs from the ultrasound estimate by more than 7 days, the ultrasound date typically takes precedence.
Most employers and FMLA guidelines use the estimated due date for leave planning, but only 5% of births occur on the exact date. Plan leave to start 1–2 weeks before the due date if possible, and confirm your HR policy for early or late delivery. Short-term disability, if applicable, typically begins on the birth date — not the due date — so the two timelines may need to be coordinated separately.
For IVF pregnancies, due date calculation differs by embryo type. For a 5-day (blastocyst) transfer: add 261 days to the transfer date. For a 3-day transfer: add 263 days. These are equivalent to adding 280 days from a calculated LMP — but using the transfer date directly is more precise since ovulation timing is known exactly. Enter the adjusted LMP equivalent into the calculator if needed.
Use the weekly milestone tracker to stay oriented between OB visits. At 20 weeks, the anatomy scan checks major organ development. At 24 weeks, the fetus reaches viability. At 28 weeks, kick counting begins. At 36 weeks, weekly cervical checks may start. Having the week-by-week view helps contextualize what each appointment is looking for and what changes to expect in symptoms.
