Last updated: April 2026
15 January 2026
10 January 2026 - 16 January 2026
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29 January 2026
This calculator provides an estimate only. Ovulation timing can vary and should not be used as medical advice or as a guaranteed fertility prediction.
Ovulation is estimated by calculating the next period date and subtracting the luteal phase length. The default is 14 days before the next period.
The fertile window is the estimated period from five days before ovulation through one day after ovulation.
Irregular cycles, stress, illness, hormonal factors, and recent contraception changes can all affect ovulation timing.
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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