Due Date Calculator
Knowing your estimated due date helps you plan prenatal care and prepare for your baby's arrival. Our due date calculator uses Naegele's rule — the standard method used by healthcare providers — to estimate your delivery date based on the first day of your last menstrual period (LMP) or your estimated conception date. It also shows your trimester breakdown and pregnancy week.
How due date calculation works
The LMP method (Naegele's rule) adds 280 days (40 weeks) to the first day of your last menstrual period. If your cycle is longer or shorter than 28 days, the estimate is adjusted accordingly. The conception method adds 266 days (38 weeks) from the estimated date of conception. Both methods provide an estimated due date, which your healthcare provider may adjust based on ultrasound measurements.
Pregnancy Essentials
Prenatal vitamins, pregnancy journals, and comfortable maternity products for every trimester.
Some links may be affiliate links. If you make a purchase, we may earn a small commission at no extra cost to you.
Frequently Asked Questions
How is a due date calculated?
How accurate are due date calculators?
What are the three trimesters?
Can my due date change?
How do I calculate my due date from conception?
More Habits Tools
View all →Habit Tracker
Track up to 10 daily habits with a visual streak counter. Build consistency, monitor your longest streaks, and develop healthier routines over time.
Period Calculator
Predict your next period, fertile window, and ovulation date based on your cycle history. View a 6-month menstrual cycle forecast.
Ovulation Calculator
Estimate your ovulation date and fertile window based on your menstrual cycle. View a 6-month fertility forecast to help you plan.
Blood Pressure Checker
Enter your blood pressure reading to see which category it falls into (normal, elevated, or high) based on AHA guidelines, with lifestyle recommendations.
Related Tools
Calorie Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation. Get calorie targets for weight loss, maintenance, and gain.
Water Intake Calculator
Calculate how much water you should drink daily based on your weight, activity level, and climate. Get a personalised hydration target in litres and glasses.
Sleep Calculator
Calculate optimal bedtimes and wake-up times based on 90-minute sleep cycles. Align your schedule to wake between cycles and feel more rested every morning.
Stress Reduction Checklist
Work through a science-backed daily stress reduction checklist. Track which stress management techniques you use and build a personalised anti-stress routine.