Fitness & Health

Due Date Calculator

Calculate pregnancy due date from last period, conception date, or IVF transfer date.

Inputs

Defaults are prefilled so the result is visible immediately.

Dating method

Known date

Results

Results update as the calculator inputs change.

Estimated due date

Nov 6, 2026

This is an estimate only and is not medical advice.

First trimester ends

May 8, 2026

Second trimester ends

Aug 7, 2026

Full-term window begins

Oct 16, 2026

Full-term window ends

Nov 13, 2026

Formula and Assumptions

Due date is derived by adding 280 days from LMP, 266 days from conception, or 261 days from a day-5 embryo transfer.

The IVF day-5 transfer rule adds 261 days from transfer.

Provider dating should override any calculator estimate.

Reference Upgrade

Built from the Calculator.net model, with added context.

Live validation and instant result updates instead of a submit-only workflow.

Multiple decision metrics are shown together, not only the primary answer.

Formula notes and assumptions are visible on the page so the math is easier to audit.

Reference Model

Modeled after the input style and primary output on Calculator.net's Due Date Calculator.

The page keeps the math in one place and exposes the assumptions beside the result.

Default inputs: method=lmp, date=2026-01-30