How accurate is this calculator?
It uses standard medical formulas. Ultrasound dating in the first trimester is the most accurate method, but LMP and conception dates provide very good estimates.
What if I don't know my exact conception date?
That's common! Use the 'First Day of Last Period' method, which is the standard way doctors date pregnancies.
Does this work for IVF pregnancies?
Yes, select the 'IVF Transfer Date' option. You can specify if it was a Day 3 or Day 5 transfer for precise calculations.
How is pregnancy weight gain calculated?
We use your pre-pregnancy height and weight to calculate your BMI, then apply the Institute of Medicine's guidelines for recommended weight gain ranges.
Can I use this for twins?
The dating timeline remains the same, but weight gain recommendations and delivery expectations (often earlier) differ for multiples. Consult your doctor for specific twin guidance.
What is 'Gestational Age'?
It's the age of the pregnancy measured from the last menstrual period. 'Fetal Age' is measured from conception and is about 2 weeks less.
Why did my due date change?
Doctors often adjust due dates based on early ultrasound measurements, which are more accurate than LMP dates if your cycle is irregular.
When should I see a doctor?
You should schedule your first prenatal appointment as soon as you have a positive home pregnancy test, usually around 8 weeks.
Is it safe to exercise?
Generally, yes! Moderate exercise is beneficial. However, always check with your healthcare provider before starting or continuing an exercise routine.
What foods should I avoid?
Avoid raw meat/fish, unpasteurized dairy, high-mercury fish, and alcohol. Limit caffeine. Our tool provides more specific nutrition tips.
How to calculate due date from last menstrual period?
To calculate due date from last menstrual period (LMP), use Naegele's Rule: add 9 months and 7 days to the first day of your last period. For example, if your LMP was January 1st, your due date is approximately October 8th. Our calculator automates this calculation—just enter your LMP date to get your estimated due date.
How to calculate pregnancy weeks from due date?
To calculate pregnancy weeks from due date, subtract your current date from the due date, then add 40 weeks (full term). For example, if your due date is October 8th and today is July 8th, you're approximately 28 weeks pregnant. Our calculator automatically calculates your current week when you enter your due date or LMP.
How many weeks am I pregnant?
To find out how many weeks you're pregnant, use our pregnancy calculator by entering your last menstrual period date, due date, conception date, or ultrasound date. The calculator will instantly show your current week of gestation, gestational age, and trimester. Most calculators use Naegele's Rule (LMP + 9 months + 7 days) or ultrasound dating for accuracy.
How to calculate gestational age?
Gestational age is calculated from the first day of your last menstrual period (LMP) to the current date. Formula: Gestational Age = (Current Date - LMP Date) in weeks and days. For example, if your LMP was 12 weeks ago, your gestational age is 12 weeks. Our calculator automatically calculates gestational age when you enter your LMP or other relevant dates.
How accurate is due date calculator?
Due date calculators using Naegele's Rule (LMP-based) are accurate within 3-5 days for women with regular 28-day cycles. Ultrasound dating in the first trimester (Crown-Rump Length) is more accurate, with accuracy within 5-7 days. However, only about 5% of babies are born on their exact due date—most arrive within two weeks before or after. Our calculator provides estimates that match standard medical calculations.
How to calculate conception date?
To calculate conception date from due date, subtract 266 days (38 weeks) from your due date. To calculate from LMP, conception typically occurs about 14 days after the first day of your last period (assuming a 28-day cycle). Our calculator includes a conception date calculator that automatically calculates conception date from various input methods.
What is a pregnancy due date calculator?
A pregnancy due date calculator is a tool that estimates your baby's due date based on your last menstrual period, conception date, ultrasound date, or IVF transfer date. Most calculators use Naegele's Rule (LMP + 9 months + 7 days) or ultrasound measurements. Our calculator supports multiple calculation methods for accurate due date estimation.
How to calculate pregnancy from conception date?
To calculate pregnancy from conception date, add 266 days (38 weeks) to your conception date to get your due date. For gestational age, count weeks from conception date (fetal age). Note: gestational age is typically measured from LMP, which is about 2 weeks before conception. Our calculator handles both gestational age (from LMP) and fetal age (from conception) calculations.
How to calculate pregnancy weeks from LMP?
To calculate pregnancy weeks from LMP (Last Menstrual Period), count the number of weeks from the first day of your last period to today. For example, if your LMP was 14 weeks ago, you're 14 weeks pregnant. Our calculator automatically calculates pregnancy weeks when you enter your LMP date, showing both weeks and days for precision.
What is Naegele's rule?
Naegele's Rule is a standard method for calculating due dates. It adds 9 months and 7 days to the first day of your last menstrual period. Formula: Due Date = LMP + 9 months + 7 days. This rule assumes a 28-day cycle with ovulation on day 14. Our calculator uses Naegele's Rule for LMP-based calculations, which is the standard method used by healthcare providers.
How to calculate IVF pregnancy due date?
To calculate IVF pregnancy due date, use the embryo transfer date instead of LMP. For Day 5 blastocyst transfers, add 263 days (37 weeks + 4 days) to the transfer date. For Day 3 embryo transfers, add 261 days (37 weeks + 2 days). Our calculator supports IVF pregnancy calculations—select the IVF transfer date option and specify Day 3 or Day 5 transfer for accurate due date estimation.
How many weeks is full term pregnancy?
Full-term pregnancy is 39-40 weeks from the last menstrual period. A baby is considered full-term at 37-42 weeks gestation. Babies born before 37 weeks are preterm, and babies born after 42 weeks are post-term. Our calculator shows your current gestational age and how many weeks remain until full term, helping you track your pregnancy progress.
How to calculate pregnancy trimester?
Pregnancy is divided into three trimesters: First trimester (weeks 1-12), Second trimester (weeks 13-26), and Third trimester (weeks 27-40). To calculate which trimester you're in, count weeks from your LMP. Our calculator automatically shows which trimester you're currently in based on your gestational age, providing trimester-specific guidance and information.
What is the difference between gestational age and fetal age?
Gestational age is measured from the first day of your last menstrual period (LMP) and is about 2 weeks more than fetal age. Fetal age (also called conception age) is measured from the actual date of conception. For example, at 12 weeks gestational age, the fetal age is approximately 10 weeks. Our calculator shows gestational age, which is the standard measurement used by healthcare providers.
How to calculate pregnancy weight gain by trimester?
Pregnancy weight gain varies by trimester: First trimester (1-4.5 lbs), Second trimester (1 lb/week or 12-14 lbs total), Third trimester (1 lb/week or 8-10 lbs total). Total weight gain depends on your pre-pregnancy BMI. Our calculator provides personalized weight gain recommendations based on your BMI and shows trimester-specific guidance for healthy weight management.
How accurate is ultrasound dating?
Ultrasound dating is most accurate in the first trimester (weeks 6-13), with accuracy within 5-7 days using Crown-Rump Length (CRL) measurements. Second trimester ultrasound (weeks 14-26) is accurate within 7-14 days. Third trimester ultrasound is less accurate for dating. Our calculator supports ultrasound-based calculations for more accurate due date estimation when ultrasound data is available.
How to calculate pregnancy days?
To calculate pregnancy days, count the number of days from the first day of your last menstrual period to today. For example, if your LMP was 100 days ago, you're 100 days pregnant (approximately 14 weeks and 2 days). Our calculator shows both weeks and days for precise pregnancy tracking, making it easy to know exactly how far along you are.
Can pregnancy calculator work for irregular periods?
Pregnancy calculators based on LMP assume a regular 28-day cycle, so they may be less accurate for irregular periods. For irregular cycles, use ultrasound dating (most accurate) or conception date if known. Our calculator supports multiple input methods (LMP, ultrasound, conception date, IVF) to provide accurate estimates even with irregular cycles—just use the most accurate date available.
How to calculate pregnancy milestones?
Pregnancy milestones are calculated based on gestational age from LMP. Key milestones include: 12 weeks (end of first trimester, lower miscarriage risk), 20 weeks (mid-pregnancy anatomy scan), 24 weeks (viability milestone), 28 weeks (third trimester begins), 37 weeks (full term). Our calculator shows important milestones and key dates for tests, scans, and baby development based on your gestational age.
What is estimated delivery date (EDD)?
Estimated Delivery Date (EDD) is another term for due date—the date your baby is expected to be born. EDD is typically calculated using Naegele's Rule (LMP + 9 months + 7 days) or ultrasound dating. Only about 5% of babies are born exactly on their EDD, with most arriving within two weeks before or after. Our calculator provides EDD estimates based on multiple calculation methods.
How to calculate pregnancy from ovulation date?
To calculate pregnancy from ovulation date, add 266 days (38 weeks) to your ovulation date to get your due date. For gestational age, add 2 weeks to your ovulation-based calculation (since gestational age is measured from LMP, which is about 2 weeks before ovulation). Our calculator can calculate pregnancy from conception/ovulation dates when you select that input method.
How many weeks until due date?
To find how many weeks until your due date, subtract your current date from your due date. For example, if your due date is 20 weeks away, you're approximately 20 weeks pregnant (halfway through pregnancy). Our calculator automatically shows weeks remaining until your due date and your current gestational age when you enter your LMP or due date.
How to calculate pregnancy progress percentage?
To calculate pregnancy progress percentage, divide your current gestational age (in weeks) by 40 (full term) and multiply by 100. For example, at 20 weeks: (20 / 40) × 100 = 50% complete. Our calculator shows your pregnancy progress including gestational age, weeks completed, and weeks remaining until your due date.
What is crown-rump length (CRL)?
Crown-Rump Length (CRL) is the measurement from the top of the baby's head (crown) to the bottom of the buttocks (rump) in the first trimester. CRL is the most accurate method for dating pregnancy, with accuracy within 5-7 days when measured between weeks 6-13. Our calculator supports ultrasound dating using CRL measurements for the most accurate due date calculation.
How to calculate pregnancy from missed period?
To calculate pregnancy from missed period, use the first day of your last menstrual period (the period before the missed one) as your LMP date. Apply Naegele's Rule (LMP + 9 months + 7 days) to get your due date. If you've just missed your period, you're approximately 4-6 weeks pregnant. Our calculator uses LMP for accurate pregnancy dating—enter the first day of your last period before the missed period.
Is pregnancy calculator free to use?
Yes, our pregnancy calculator is completely free with no charges, subscriptions, or registration required. You can calculate unlimited due dates, track your pregnancy progress, access all features (gestational age, trimester guidance, weight gain recommendations), and use the tool for personal pregnancy tracking without any cost. All features are available without limitations.
Can I use pregnancy calculator on mobile?
Yes! Our pregnancy calculator is fully responsive and works perfectly on mobile devices, tablets, and desktop computers. The calculator is optimized for touch screens, making it easy to enter dates and view results on the go. You can use it during your pregnancy journey for tracking progress, checking milestones, or monitoring your due date, wherever you are.
How accurate is pregnancy weight gain calculator?
Our pregnancy weight gain calculator uses Institute of Medicine (IOM) guidelines based on pre-pregnancy BMI, which are the standard recommendations used by healthcare providers. The recommendations are accurate for general guidance, but individual circumstances vary. Always consult your healthcare provider for personalized weight gain recommendations, especially for high-risk pregnancies or specific health conditions.
What is the best pregnancy calculator?
The best pregnancy calculator is free, accurate, easy to use, supports multiple calculation methods (LMP, ultrasound, conception, IVF), provides comprehensive information (due date, gestational age, trimester, weight gain), works on all devices, processes data locally for privacy, and offers regular updates. Our calculator meets all these criteria—it's completely free, accurate, user-friendly, and privacy-focused, making it perfect for pregnancy tracking.