Uptime monitoring
Understanding uptime metrics
Response time, status codes, and uptime percentage.
Overview
Each monitor surfaces three headline numbers: uptime percentage, response time, and the last status code. Here's how each is calculated.
Uptime percentage
Uptime percentage shows how often your service was available over a time period. It's calculated as:
Uptime % = (Successful checks / Total checks) × 100| Uptime | Monthly downtime |
|---|---|
| 99.9% | ~43 minutes |
| 99.5% | ~3.6 hours |
| 99.0% | ~7.2 hours |
| 95.0% | ~36 hours |
Response time
Response time measures how long it takes to receive a response from your service. Checkmate shows:
- Current: The most recent response time
- Average: Mean response time over the period
- P95: 95th percentile (95% of requests were faster)
Status codes
For HTTP monitors, Checkmate tracks response status codes. A check is considered successful if the status code matches your expected codes (default: 200).