Pregnancy Due Date Calculator
healthEstimate delivery date (EDD), gestational age, and fetal development size based on Naegele's rule.
Sunday (196 days to go)
How Pregnancy Due Dates are Calculated: Naegele's Rule
The standard clinical benchmark for estimating expected delivery date (EDD) is Naegele's Rule, which adds 280 days (40 gestational weeks) to the first day of the last normal menstrual period (LMP).
Only about 5% of babies arrive on their exact predicted date; a full-term pregnancy naturally spans between 37 and 42 weeks.
How to Use & Features
The Pregnancy Due Date Calculator computes output instantly as you type with zero reload. All conversions and calculations strictly adhere to international standards.
- Input your value into the designated input field.
- Select your source and target units from the dropdown menus.
- Click the copy button beside the result to copy to your clipboard.
Calculation Principle & Formula
This tool utilizes precision floating-point arithmetic with normalization via standard reference bases to avoid rounding discrepancies.
Frequently Asked Questions
Q. Are the calculation results reliable?
Yes, calculations are rigorously verified against international measurement standards and engineering equations.
Q. Does this work smoothly on mobile devices?
Yes, CalcZen is fully responsive and tailored for smartphones, tablets, and desktop computers.