FORMULA
How the calculation works
Estimated due date = LMP date + 280 days
Use consistent units and review the assumptions shown beside the result.
FITNESS & HEALTH / FREE ONLINE TOOL
Due Date Calculator
Estimate a pregnancy due date from the first day of the last period.
INPUT
LOCAL CALCULATIONEnter your values
RESULT
FORMULA v1.0.0Your calculation
ResultReady
ADVERTISEMENT
EXAMPLE
Worked example
Enter your values to receive an instant result with a clear breakdown.
Formula reviewed July 30, 2026 · Version 1.0.0
FAQ
Frequently asked questions
Is this calculator free?
Yes. It is free to use and does not require an account.
Are my values uploaded?
No. This calculation runs locally in your browser.
SOURCE & LIMITS
Methodology
Standard mathematical and industry formulas. Results are estimates for planning purposes.
Results are estimates. Confirm measurements, product specifications and professional requirements before making critical decisions.