What This Tool Does

Sedentary Time Calculator helps you estimate daily sitting duration and risk level. It supports both custom time blocks and quick workday/weekend estimation, then provides stand-up break targets and practical reduction tips.

How to Use

1. In "Calculate by Time Blocks", fill start and end time for each block, then click "Calculate Sitting Time".
2. Or enter workday and weekend sitting hours in "Quick Estimate", then click "Quick Calculate".
3. Review daily and weekly sitting hours, suggested break count, and risk interpretation.
4. Use the reduction tips and health impact section to plan habit changes.

Calculation Rules

• Time-block mode merges overlapping intervals to avoid double counting.
• Invalid intervals (end time earlier than or equal to start time) are ignored with a notice.
• Quick estimate uses ((workday hours 5) + (weekend hours 2)) / 7 for daily average.
• Suggested stand-up breaks are estimated at one break every 45 minutes.

Risk Bands

• Low risk: under 4 h/day.
• Moderate risk: 4 to under 7 h/day.
• High risk: 7 to 10 h/day.
• Very high risk: over 10 h/day.

Notes

• Results are for self-management reference and not medical diagnosis.
• Track continuously and compare trends with your real routine.
• All calculations run locally in your browser.