Due Date Calculator Wheel

The Due DateWheel Calculator estimates your Estimated Due Date based on your first day of the last menstrual period and cycle length. This tool helps expectant parents track pregnancy progress and plan for the big day. Whether you are confirming a conception date or preparing for maternity leave, this calculator offers reliable timeline estimates.

First Day of Last Menstrual Period Enter the first day of your last menstrual period. This is typically 2 weeks before conception.

Average Menstrual Cycle Length (days) Enter the average length of your menstrual cycle in days. The default is 28 days.

Calculation Method

Alternative Date (if applicable) For ultrasound, IVF, or conception date calculations, enter the relevant date here.

I have irregular periods

Quick Examples:

How Estimated Due Date Is Calculated

The Estimated Due Date predicts the approximate day your baby will be born. Most calculations use Naegele’s Rule, which estimates the delivery date by adding 280 days to the first day of your last menstrual period.

LMP + 280 Days = Due Date

Where:

LMP = First day of the Last Menstrual Period
280 Days = Average length of pregnancy (40 weeks)

First, the tool uses your LMP as the starting point for the 40-week timeline. Then, it adjusts this date if your cycle length is longer or shorter than the standard 28 days. This fine-tunes the ovulation date for better accuracy. If you select the ultrasound method, the calculation relies on fetal measurements instead of the LMP.

Pro Tip

If you know your conception date or IVF transfer date, use those inputs for a more precise calculation, as they bypass the variability of menstrual cycles.

While these formulas provide a reliable estimate, only about 5% of babies are born exactly on their due date.

What Your Estimated Due Date Means

This date serves as a target for your delivery and helps you track your baby's development week by week.

Planning for Delivery

A full-term pregnancy lasts between 39 and 40 weeks. Use your due date to schedule maternity leave, install the car seat, and have your hospital bag ready by week 37. It ensures you are prepared when labor begins.

Tracking Development

Knowing your week count helps you understand your baby's growth stages. You can see which size fruit they compare to this week and what developmental milestones to expect during each trimester.

Medical Scheduling

This date helps you plan prenatal visits and necessary screenings. For example, doctors often recommend anatomy scans around week 20 and glucose testing later in the pregnancy.

Important: If you have irregular periods, the LMP estimate might be less precise. In such cases, an early ultrasound often provides a more accurate due date.

Disclaimer: This calculator is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider regarding your specific due date and prenatal care plan.

Keep a log of your pregnancy symptoms and milestones to discuss with your doctor at your next checkup.