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Sync settings

Choose what your account keeps in step on every device where you are signed in.

  • My tools

    Always synced: the tools on your board, their order and size.

  • The windows open on your start page, including what you typed in them.

  • Every note in the notepad – on the notepad page, on your board and in windows.

  • Every list of website shortcuts – on the shortcuts page, on your board and in windows.

  • Every grid in the cover grid maker – on its page, on your board and in windows.

  • Every list of bookmarked organisations in the OIN lookup – on its page, on your board and in windows.

  • Keeps your pipeline and saved recipes on all your devices. Your files are never synced – only the steps and settings.

Turning something off removes it from your account straight away. Your devices keep their own copy.

Notifications

Tools that can tell you about something new while a Synsi tab is open, even when you are in another tab or app. Choose them for this browser.

This browser cannot show notifications from websites.
Notifications are blocked for this site. Allow them in your browser’s site settings (the icon left of the address), then switch them on here.

  • Says “New message” while a Synsi tab is open – never who wrote it or what.

Your choice is stored in this browser only. Notifications never show personal content such as a message or a number. They work while a Synsi tab is open; closed tabs get none.

Browse all tools →

Ovulation Calculator

Estimate ovulation and a fertile window from period date and cycle length.

My tools →
days

Fertile window starts

Estimated ovulation

Fertile window ends

Cycle estimates vary and must not be used to prevent pregnancy.

Runs in your browser – your data never leaves your device Also available via our free API

How to use the Ovulation Calculator

  1. 1 Enter the requested details.
  2. 2 Review the estimate and the limitations shown with it.

How the estimate works

The estimate places ovulation about 14 days before the next expected period, then shows the five days before through one day after as an estimated fertile window. Cycle timing varies. This calculator cannot confirm ovulation and must not be used as contraception. Source: American College of Obstetricians and Gynecologists.

How to use this calculator

Enter the requested values and review the result alongside the limits of the estimate.

Important limitations

This result is for general information. Individual circumstances can change what is appropriate; consult a qualified professional when making health decisions.

Frequently asked questions

How does this calculator work?

The estimate places ovulation about 14 days before the next expected period, then shows the five days before through one day after as an estimated fertile window. Cycle timing varies. This calculator cannot confirm ovulation and must not be used as contraception. Source: [American College of Obstetricians and Gynecologists](https://www.acog.org/womens-health/faqs/fertility-awareness-based-methods-of-family-planning).

Is this a diagnosis or personalized advice?

No. This is an informational estimate and does not replace professional advice.

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