Fertility Calendar
Calculate your fertile window, ovulation date, and key cycle dates based on your last period and cycle length.
Typical range: 21-35 days
How the Fertility Calendar Works
Ovulation typically occurs about 14 days before your next period. The fertile window spans approximately 5 days before ovulation and 1 day after. This calculator estimates these key dates based on your cycle length and the first day of your last period.
Features
- Ovulation date prediction
- Fertile window calculation
- Implantation window estimation
- Pregnancy test timing recommendation
- 100% private - all calculations run locally
Disclaimer: This tool is provided “as is” for informational and educational purposes only. Results may not be 100% accurate. ToolBird makes no warranties, express or implied, regarding the accuracy, reliability, or completeness of any output generated by this tool. This tool does not constitute professional, legal, financial, medical, or tax advice. Always consult a qualified professional for important decisions. By using this tool, you agree that ToolBird and its operators shall not be held liable for any damages, losses, or consequences arising from the use of this tool or reliance on its results. All processing occurs in your browser — we do not store, transmit, or access your data. Use at your own risk.