Pregnancy due date calculator
Calculate due date, weeks pregnant and trimester.
Our pregnancy due date calculator computes instantly as you type and shows every intermediate result so you understand the math. Free, no sign-up, works on any device.
Formula: Naegele’s rule: due date = first day of last period + 280 days (adjusted for cycle length).
Pregnancy due date calculator: how to use it
- Enter your values (you can switch units).
- The result is calculated automatically.
- Review the breakdown and results table.
- Copy the result in one click.
Features
- Real-time calculation.
- Detailed breakdown and tables.
- Metric and imperial units.
- Private: nothing leaves your browser.
Frequently asked questions
Are the results accurate?
We use standard formulas with double-precision math. For important financial or medical decisions, consult a professional.
Do you store my data?
No. Calculations run in your browser.
Can I use it on my phone?
Yes, it is mobile-optimized.