Privacy Policy
Last updated: March 7, 2026
Your privacy is important to us. This policy explains how we collect, use, and protect your personal information when you use Period Calculator.
Data We Collect
Period Calculator is designed with privacy as our top priority. When you use our service, we collect minimal data necessary for functionality:
- First day of your last period (for cycle calculation)
- Average cycle length (for prediction accuracy)
- Period duration (for better predictions)
- Language and theme preferences (stored locally)
How We Store Your Data
All your data is stored locally on your device using browser storage. We never upload your personal data to any server.
- Data is stored in your browser's localStorage
- Data never leaves your device
- You can delete your data at any time by clearing browser cache
- No account or login required
How We Use Your Data
Your data is used exclusively to provide our core services:
- Calculate your next period date
- Predict your fertile window and ovulation day
- Generate calendar events for your predictions
- Remember your preferences (theme, language)
Cookies
We use minimal cookies solely for essential functionality:
- Theme preference (light/dark mode)
- Language selection
- These are functional cookies, not tracking cookies
Third-Party Services
We integrate with trusted third-party services to enhance your experience:
- Google Calendar (for adding events) - data is sent directly from your device to Google
- No data is shared with advertising networks
- No analytics or tracking services
Your Rights
You have complete control over your data:
- Access your data at any time
- Delete your data instantly (clear browser cache)
- Export your data (not applicable as data stays on your device)
- Opt-out by simply not using the app