# Session Duration

**Category:** metrics  
**Short Description:** The length of time a user spends actively engaged during a single website visit.  
**Last Updated:** 2024-03-15

## Definition

Session duration measures the time span between a user's first and last interaction within a single session, tracking active engagement through page views, clicks, and other interactions. This metric helps evaluate content quality, user engagement depth, and overall site effectiveness in maintaining user interest.

## Calculation

**Formula:** `Last Interaction Timestamp - First Interaction Timestamp`

**Explanation:** Calculated as the time difference between the first and last tracked interaction, excluding inactive periods and typically limited by a session timeout (usually 30 minutes of inactivity).

### Components

- **Last Interaction**: Final tracked activity before session timeout or exit
- **First Interaction**: Initial pageview or event that starts the session

## Examples

- Average session duration of 4:30 on content sites indicating strong engagement
- E-commerce session duration of 8:45 suggesting detailed product research
- Social platform sessions averaging 12:20 showing high user involvement

## Related Terms

### Opposite Terms

- **[Bounce Rate](/resources/glossary/metrics/bounce-rate)**: Single-page sessions impact average duration calculations

### Similar Terms

- **[Landing Page Optimization](/resources/glossary/general/landing-page-optimization-lpo)**: LPO aims to increase session duration through engaging content and clear user paths
- **[Engagement Rate](/resources/glossary/metrics/engagement-rate)**: Both metrics indicate how effectively content holds user attention