Calculate your pregnancy due date and track your baby’s development week by week. Simply enter your last menstrual period (LMP) date or conception date to get your estimated due date, current pregnancy week, and trimester information.
While only about 5% of babies arrive exactly on their due date, knowing your estimated delivery date helps you and your healthcare provider plan important prenatal visits, tests, and prepare for your baby’s arrival.
Pregnancy Due Date Calculator
Figure out when your baby is likely to arrive. Most pregnancies last about 280 days (40 weeks) from the first day of your last period, though only about 5% of babies actually arrive on their exact due date.
Calculate Your Due Date
Understanding Your Pregnancy Journey
Here's something most pregnancy books won't tell you upfront: that "40 weeks" everyone talks about? It's more of a suggestion than a deadline. Think of your due date as a "due week" or even a "due month." Sarah, a first-time mom from California, describes her experience perfectly: "I packed my hospital bag at 36 weeks and waited... and waited... and then waited two more weeks! My daughter clearly had her own schedule in mind."
The fascinating part is how doctors actually calculate pregnancy. They count from the first day of your last period—which seems odd when you think about it, since you weren't technically pregnant yet! This medical quirk dates back to the 1800s when German obstetrician Franz Naegele created the "Naegele's Rule" (your due date = first day of last period + 280 days). It stuck because it's remarkably accurate for women with regular 28-day cycles, even though every woman's body operates on its own unique timeline.
What makes pregnancy prediction so challenging? Your baby isn't reading any calendars. Some perfectly healthy babies need 37 weeks to cook, others take the full 42 weeks. Factors like genetics (if your mom had quick labors, you might too), your health, stress levels, and even the baby's position all play a role. One obstetrician compared it to baking bread: "You can set a timer, but the bread is done when it's done, not when the buzzer goes off."
The good news? Modern medicine gives us amazing tools beyond just calendar counting. Early ultrasounds (between 8-13 weeks) can predict your due date within 3-5 days accuracy. That's why your doctor might "change" your due date after the first ultrasound—they're not changing when conception happened, they're just getting a more precise measurement based on your baby's actual size. It's like the difference between guessing someone's age and checking their birth certificate.
Pregnancy Development by Week
First Trimester (Weeks 1-12)
Your Baby's Incredible Start: Imagine building a house from blueprint to move-in-ready in just 12 weeks—that's essentially what your baby accomplishes in the first trimester. Week 6 brings one of pregnancy's most magical moments: your baby's heart begins beating, usually around 110-120 beats per minute (nearly twice your own heart rate!). By week 8, what started smaller than a poppy seed now has recognizable arms, legs, and even tiny fingers forming. The transformation from a cluster of cells to a lime-sized baby with all major organs in place happens so rapidly, it's almost hard to believe.
What You Might Experience: The first trimester often catches women off guard. As one mom described it: "I felt like I had the flu, but knowing it was actually tiny fingers and toes forming inside me made it bearable—barely!" Morning sickness (which, ironically, can strike any time of day) affects about 70% of pregnant women. The exhaustion is real too—your body is building a placenta, essentially a whole new organ. No wonder you feel like you could nap standing up! Many women also experience breast tenderness that makes even hugging uncomfortable, and you might find yourself mapping out every bathroom between home and work. These symptoms aren't fun, but they're signs your pregnancy hormones are doing exactly what they're supposed to.
Second Trimester (Weeks 13-27)
The "Golden Trimester" for Your Baby: Around week 16, something remarkable happens—your baby can hear you! Not clearly, more like you sound underwater, but your voice becomes their favorite lullaby. By week 20, they're developing their own personality with distinct sleep-wake cycles (which unfortunately may not match yours). Hair sprouts on their head, eyebrows appear, and those tiny fingernails you'll soon be trimming are growing. From a peach-sized bundle at week 13 to a full cauliflower by week 27, this growth spurt is extraordinary. Some moms even notice their baby responding to music or reacting when their partner talks—early signs of bonding before birth.
Your "Honeymoon Phase": Many women call this the best trimester, and with good reason. That bone-deep exhaustion from the first trimester? Often gone. The nausea that made you avoid entire sections of the grocery store? Usually fading. Your energy returns, your appetite comes back with a vengeance, and you finally look unmistakably pregnant instead of like you ate too much lunch. But the absolute highlight? Somewhere between weeks 16-25, you'll feel those first fluttery movements—called "quickening" because it feels like butterfly wings or popcorn popping. First-time moms often wonder "Was that the baby or just gas?" (Spoiler: if it's rhythmic and gentle, it's probably your little gymnast saying hello!)
Third Trimester (Weeks 28-40)
Final Preparations for Your Baby: The third trimester is when your baby transforms from "could survive with medical help" to "ready for the world." Their brain undergoes explosive growth—forming billions of neural connections every day. Around week 36, the lungs produce surfactant, a substance that allows them to breathe air for the first time. Their bones harden everywhere except the skull (which stays soft and flexible for delivery—nature's brilliant engineering!). By week 40, that eggplant-sized baby from week 28 has grown into a full watermelon, weighing anywhere from 6-9 pounds on average. The final weeks are essentially a "fattening up" period where baby adds the adorable chubby cheeks you'll kiss countless times.
The Home Stretch for You: Let's be honest—the third trimester isn't always comfortable. With a baby the size of a watermelon pressing on your lungs, climbing stairs can feel like running a marathon. Many women experience back pain as their center of gravity shifts forward. You might also notice "practice contractions" called Braxton Hicks—your uterus doing trial runs for the main event. Sleep becomes an Olympic sport as you try to find a comfortable position. One mom joked: "I felt like a beached whale trying to roll over in bed!" But here's the silver lining: every uncomfortable symptom means you're that much closer to meeting your baby. Your body is preparing for labor, your nesting instinct kicks in (suddenly organizing the baby's closet at 2 AM seems urgent), and anticipation builds. This is the final countdown!
Nutrition During Pregnancy
You're Not Really "Eating for Two": Here's a pregnancy myth worth busting: you don't need to double your calories! In the first trimester, you don't need extra calories at all. Second trimester requires only about 340 additional calories daily (think: a banana with peanut butter), and third trimester needs around 450 extra calories (a bowl of oatmeal with berries). What matters far more than quantity is quality—those extra calories should pack a nutritional punch because your baby is literally built from what you eat.
The Nutrients That Matter Most: Think of folic acid as your baby's neural tube architect—it prevents major birth defects and you need 400-800 mcg daily (found in fortified cereals, spinach, and oranges). Iron becomes crucial because you're producing 50% more blood than usual; aim for 27 mg daily through lean meats, beans, and fortified grains. Calcium builds those tiny bones, DHA (omega-3) supports brain development, and protein forms every cell in your growing baby. A diverse, colorful plate usually covers all bases better than any supplement alone.
Pregnancy Superfoods
Load up on leafy greens like spinach and kale (folate powerhouses), wild-caught salmon (brain-boosting DHA), Greek yogurt (protein and probiotics), sweet potatoes (vitamin A for baby's eyes), eggs (complete protein and choline), and colorful berries (antioxidants). Whole grains provide sustained energy, while nuts and legumes offer protein and healthy fats. Your plate should look like a rainbow!
The "No-Fly Zone" Foods
Some foods carry risks that aren't worth taking: raw or undercooked meat/eggs (salmonella risk), high-mercury fish like shark, swordfish, and king mackerel (mercury damages developing brains), unpasteurized dairy or juices (listeria risk), alcohol (no safe amount during pregnancy), and excessive caffeine (keep under 200mg daily—about one 12oz coffee). Deli meats are risky unless heated steaming hot due to listeria concerns. When in doubt, cook it thoroughly!
About Those Weird Cravings
Pickles and ice cream? Chalk? Dirt? Pregnancy cravings range from amusing to alarming. Most are harmless—if you want watermelon at midnight, enjoy! But craving non-food items (called pica) like dirt, clay, or laundry starch could signal iron deficiency—tell your doctor. Some theories suggest cravings reflect nutritional needs, but science is mixed. One thing's certain: if you're craving it and it's food-safe, a small indulgence usually satisfies without guilt.
Safe Exercise During Pregnancy
Moving Your Body (Yes, Really!): Contrary to old advice about putting your feet up for nine months, modern medicine enthusiastically encourages exercise during pregnancy. Active pregnant women typically experience less back pain, sleep better despite the basketball belly, maintain better moods (those endorphins fight pregnancy hormones!), often have easier labors, and bounce back faster postpartum. The American College of Obstetricians and Gynecologists recommends 150 minutes of moderate exercise weekly—that's just 30 minutes, five days a week. You're not training for a marathon (please don't!), but staying active benefits both you and baby.
🏃♀️ The Best Pregnancy Workouts
Walking is pregnancy gold—free, safe all nine months, and you can do it anywhere. Many moms walk right through contractions to help labor progress! Swimming feels like magic when you're pregnant; the water supports your weight, and you feel almost weightless again. It's a full-body workout without joint stress. Prenatal yoga builds flexibility for delivery, teaches breathing techniques you'll use during labor, and offers mental relaxation. Stationary cycling provides cardiovascular fitness without the fall risk of outdoor biking. Light weight training maintains the muscle tone you'll desperately need for carrying a car seat and stroller up stairs later!
⚠️ The Exercise "No" List
Some activities carry too much risk when you're growing a human. Skip contact sports (soccer, basketball) where you could get hit in the belly. Avoid activities with high fall risk like skiing, horseback riding, or gymnastics—your changing center of gravity makes you clumsier than usual. Hot yoga and saunas can raise your core temperature to dangerous levels for baby. After your first trimester, don't lie flat on your back for extended periods; it compresses a major blood vessel. And while you can continue high-intensity workouts if you did them pre-pregnancy, this isn't the time to start CrossFit. Listen to your body—if something feels wrong, stop.
💡 Smart Exercise Tips
Stay hydrated (dehydration triggers contractions), avoid overheating, stop if you feel dizzy or short of breath, and remember the "talk test"—you should be able to hold a conversation while exercising. Your ligaments are looser thanks to pregnancy hormones, so avoid bouncing or jerky movements. Most importantly, get your doctor's clearance, especially if you have pregnancy complications. Exercise should feel energizing, not exhausting!
Common Pregnancy Symptoms
The Good, The Bad, and The Weird: Pregnancy symptoms are like a grab bag—every woman gets a different mix. Some sail through nine months glowing and energetic. Others feel like they're on a turbulent boat ride through hormone seas. Neither experience is "wrong"; your body's response to pregnancy is as unique as your baby's fingerprints. Understanding what's normal can prevent midnight Google panic sessions (we've all been there!).
What to Expect Throughout Pregnancy
Morning sickness (which laughably can strike any time of day) ranges from mild queasiness to severe vomiting. The peak? Usually weeks 8-10. Try eating small, frequent meals and keeping crackers by your bed. Breast tenderness often appears before you even know you're pregnant—one woman described it as "feeling like someone punched my boobs." Your breasts are preparing to feed a baby; tenderness is just part of the transformation.
Fatigue in the first trimester isn't regular tiredness—it's bone-deep exhaustion where you could fall asleep standing up. This makes sense: you're building a placenta from scratch! By the second trimester, energy usually returns. Food aversions can be bizarre and sudden. The smell of coffee, once beloved, might make you nauseous. One mom couldn't stand the smell of her husband's soap for six months! These usually resolve after delivery.
Later symptoms include heartburn (that growing baby pushes stomach acid up), swollen ankles (extra fluid and pressure), frequent urination (baby tap-dancing on your bladder), and Braxton Hicks contractions (practice squeezes that feel like menstrual cramps). The third trimester might bring shortness of breath, insomnia, and general discomfort. It's your body's way of preparing you for sleepless nights with a newborn—silver lining?
⚠️ When to Call Your Doctor Immediately
Most symptoms are annoying but normal. However, some demand immediate medical attention: severe or persistent vomiting (you can't keep anything down and are dehydrated), any vaginal bleeding (especially with cramping), severe abdominal pain that doesn't ease, high fever over 101°F (fever can harm baby's development), sudden severe headaches (could indicate preeclampsia), vision changes like blurriness or seeing spots (another preeclampsia sign), and decreased fetal movement after 20 weeks (if baby's usually active but goes quiet, get checked immediately). Trust your gut—if something feels very wrong, call your provider. They'd rather reassure you than miss something important.
Prenatal Appointment Schedule
Your Roadmap Through Prenatal Care: Regular prenatal visits aren't just checking boxes—they're crucial safety checkpoints for you and your baby. The schedule intensifies as pregnancy progresses because different complications emerge at different stages. Early appointments focus on establishing a healthy pregnancy foundation; later visits monitor for issues like preeclampsia or growth problems. Think of your OB/GYN as your pregnancy copilot, helping navigate this nine-month journey safely.
📅 First Trimester: The Foundation (Weeks 1-12)
Your first visit around weeks 8-10 is comprehensive—medical history, physical exam, blood work, and usually your first ultrasound where you'll hear that miraculous heartbeat. Many providers offer NT (nuchal translucency) scans between weeks 10-12 and first trimester screening (weeks 11-13) to assess chromosomal abnormality risks. These early appointments establish your baseline health and confirm your due date. Pro tip: Bring your partner or a support person—hearing the heartbeat together is unforgettable!
📅 Second Trimester: The Monitoring Phase (Weeks 13-27)
Appointments typically happen monthly (every 4 weeks) during this "honeymoon trimester." Around weeks 15-20, you might have a quad screen (blood test checking for neural tube defects and chromosomal issues). The highlight? The anatomy ultrasound (weeks 18-22) when you can find out your baby's sex (if you want to know) and doctors examine every organ, limb, and structure. Between weeks 24-28 comes the glucose screening—you'll drink a super-sweet beverage and have blood drawn to check for gestational diabetes. Fair warning: that drink is NOT delicious.
📅 Third Trimester: The Home Stretch (Weeks 28-40+)
Visits intensify to every 2 weeks from weeks 28-32, then weekly from week 36 onward. Around week 35-37, you'll get the Group B strep test (a quick vaginal/rectal swab—not fun, but necessary). Final weeks include cervical checks (optional) to see if you're dilating and frequent monitoring of baby's heart rate and your blood pressure. If you go past your due date, expect twice-weekly monitoring (weeks 40+) with non-stress tests and ultrasounds to ensure baby's thriving. These appointments might feel excessive, but they catch potential problems early when intervention makes the biggest difference.
💡 Making the Most of Your Appointments
Keep a running list of questions on your phone (you WILL forget them otherwise!). Bring your partner to key appointments like the anatomy scan. Don't be shy about asking "dumb" questions—your doctor has heard them all. If something concerns you between appointments, call! That's what they're there for. Finally, remember that every pregnancy is unique; your friend's experience might differ entirely from yours, and that's perfectly normal.
Ready for Your Pregnancy Journey?
Get personalized pregnancy guidance and connect with healthcare professionals.
About This Calculator: This pregnancy calculator provides estimated due dates based on medical standards, but remember—only about 5% of babies arrive on their exact due date. Your healthcare provider uses multiple factors including ultrasounds, physical exams, and your unique medical history for the most accurate assessment. Think of this tool as a helpful planning guide that complements (but never replaces) the personalized care you receive during prenatal visits. Every pregnancy is beautifully unique, just like the baby you're growing!