Calculate Your Due Date
How Due Date is Calculated
Naegele's Rule: The standard method adds 280 days (40 weeks) to the first day of your last menstrual period (LMP).
From Conception: If you know your conception date, add 266 days (38 weeks) since fertilization occurs about 2 weeks after LMP.
Cycle adjustment: If your cycle is longer or shorter than 28 days, the calculator adjusts the due date accordingly.
Important Milestones
- Week 12: End of first trimester, risk of miscarriage decreases
- Week 20: Anatomy scan, often when sex can be determined
- Week 24: Viability milestone
- Week 37: Considered early term
- Week 39-40: Full term, optimal for delivery
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are estimates and should not replace professional medical advice.
Related Tools
- Blood Pressure Calculator -- Check blood pressure readings against AHA categories with visual gauge
- Pregnancy Due Date Calculator -- Estimate your due date and track pregnancy milestones from LMP, conception, or
- Calories Burned Calculator -- Estimate calories burned from any activity
- Pregnancy Weight Gain Calculator -- Track recommended weight gain during pregnancy based on pre-pregnancy BMI and
Related Tools
View all toolsBMI Calculator
Calculate Body Mass Index from height and weight
BMR Calculator
Estimate basal metabolic rate (BMR)
Body Fat Calculator
Estimate body fat percentage from BMI
Calorie Needs Calculator
Estimate daily calories by activity level
Ideal Weight Calculator
Estimate ideal weight from height
Pace Calculator
Calculate running pace and race finish times
Due Date Calculator FAQ
What is Due Date Calculator?
Due Date Calculator is a free health tool that helps you Calculate pregnancy due date from LMP or conception.
How do I use Due Date Calculator?
Enter your input values, review the calculated output, and adjust inputs until you reach the result you need. The result updates in your browser.
Is Due Date Calculator private?
Yes. Calculations run locally in your browser. Inputs are not uploaded to a server by default, and refreshing the page clears session data.
Does Due Date Calculator require an account or installation?
No. You can use this tool directly in your browser without sign-up or software installation.
How accurate are results from Due Date Calculator?
This tool applies standard formulas or deterministic processing logic for estimates. For medical, legal, tax, or investment decisions, verify with a qualified professional.
Can I save or share outputs from Due Date Calculator?
You can bookmark this page and copy outputs manually. Results are not persisted in your account and are typically not embedded in the URL.