Calculate your estimated due date and current gestational age using the first day of your last menstrual period (LMP).
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Due Date Summary
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The estimated due date is calculated as 40 weeks (280 days)from the first day of your last menstrual period, adjusted for cycle length. Actual delivery can vary by ±2 weeks.
⚡ Note: This tool provides an estimate and should not replace professional medical advice. Always consult your healthcare provider for personalized information.
The Journey Begins: Understanding Your Estimated Due Date (EDD)
An Estimated Due Date (EDD) is not a fixed appointment, but a scientific window into your baby’s arrival. Only about 4% of babies are born exactly on their due date. However, calculating this date is crucial for monitoring fetal development milestones and planning medical care.
Most healthcare providers calculate the due date based on the first day of your Last Menstrual Period (LMP). If you have been tracking your cycle closely, you might find our Conception Calculator more precise for pinpointing the exact moment your journey began.
Nurturing Life: The Caloric Shift
As your due date approaches, your body’s metabolic demands undergo a massive transformation. It is a myth that you need to "eat for two" in the first trimester, but as you progress, your energy needs spike:
1Metabolic Base: Your BMR increases by nearly 15-20% by the third trimester. Keeping track of this helps in avoiding excessive fatigue.
2Protein for Growth: Every cell of your baby requires amino acids. Use our Protein Calculator to ensure you are meeting the increased demand for fetal tissue and placenta development.
3Healthy Weight Gain: Monitoring your BMI before and during pregnancy ensures that weight gain stays within a safe, clinical range.
Fitness & Delivery Preparation
Staying active is key to a smoother delivery. However, your heart works harder during pregnancy. It is vital to monitor your Target Heart Rate to ensure you are not over-exerting yourself or the baby.
"Did you know? Light walking can improve circulation. Check your Walking Pace to maintain a healthy, low-impact exercise routine."
The Three Trimesters: What to Expect
First Trimester
Week 1-12: The foundation. Vital organs begin to form. Use our Full Pregnancy Tracker to see weekly baby size updates.
Second Trimester
Week 13-26: The "golden period." Energy returns. This is the best time to check your Calorie Needs to support rapid fetal growth.
Third Trimester
Week 27-Birth: The home stretch. Focus on nutrition and rest. Keep an eye on your Target Weight milestones.
Why Your Due Date Might Change
It is very common for a doctor to adjust your due date after an early ultrasound (dating scan). Ultrasounds measure the "Crown-Rump Length," which is the most accurate way to date a pregnancy in the first 12 weeks. If your cycle is irregular, your LMP-based date might differ from your conception date significantly.
Factors like maternal age, pre-pregnancy Body Fat Percentage, and previous pregnancies can also influence whether you deliver slightly early or late.
Due Date & Pregnancy FAQ
How accurate is a due date calculator?
It provides a solid estimate based on a 28-day cycle. For a more personalized view, combine it with our Conception Tool if you know your ovulation date.
Can exercise affect my due date?
Moderate exercise is healthy, but avoid reaching your 1RM (One-Rep Max) during pregnancy. Low-impact movements are safer for the pelvic floor.
What if I miss my due date?
Going past 40 weeks is common, especially for first-time mothers. Your doctor will monitor the baby's heart rate and amniotic fluid levels closely.
Does my pre-pregnancy weight matter?
Yes. Women with a high BMI or low muscle mass may have different nutritional requirements. Use our Protein Guide to plan better.
Preparing for the "Fourth Trimester"
Post-Pregnancy Recovery: Once the baby arrives, your BMR will stay elevated if you are breastfeeding. Don't rush into a deficit; focus on nutrient density.
Rebuilding Strength: After medical clearance, use the Ideal Weight Tool to set gentle, long-term goals for regaining your fitness.