yCalculator

Conception Calculator

Last updated: April 2026

Method

days

Estimated conception date

15 January 2026

Estimated ovulation date

15 January 2026

Fertile window

10 January 2026 - 16 January 2026

Estimated due date

8 October 2026

Medical note

This calculator provides an estimate only. Conception timing cannot be known exactly from dates alone and should not be used as medical confirmation.

Related calculators:

  • Pregnancy Conception Calculator
  • Ovulation Calculator
  • Due Date Calculator
  • Period Calculator

What is a conception calculator?

A conception calculator estimates ovulation timing, a possible conception date, and a fertile window from cycle dates or a due date.

How is conception date estimated?

The last-period method estimates ovulation from cycle length. The due-date method estimates conception by subtracting 266 days from the due date.

Why conception dates are approximate

Ovulation and fertilisation timing vary, and sperm can survive for several days. Dates alone cannot prove exact conception timing.

What does this mean?

This calculator is designed to help you understand the likely number before you make a decision or start an application.

Your result should be checked against official UK guidance, especially if your circumstances include dependants, exemptions, prior leave, or a complex immigration history.

Treat the figure as a planning tool rather than legal advice. Where the answer affects an application deadline or major payment, speak to an authorised adviser.

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