Wulaoer Tools

Due Date Calculator

Estimate a delivery date with Naegele's rule and view the trimesters.

Calculation method

Due date = last period + 280 days.

This is an estimate based on average cycle length. Actual delivery varies. For reference only — not medical advice.

Result

Enter a date to see the estimate.

How to use

  1. 1Enter the first day of your last period, or a conception date.
  2. 2Read the estimated due date and the trimester boundaries.
  3. 3For reference only, not medical advice.

Examples

LMP 2026-01-01
Estimated due date around 2026-10-08.