Uptime SLA Calculator
A practical reference for teams that need to translate an uptime percentage into a downtime budget.
Uptime SLA Calculator from Sandglass helps you translate an uptime percentage into a downtime budget. Use the result to decide what to monitor continuously.
When to reach for this tool
Reach for this when you need to translate an uptime percentage into a downtime budget during setup, debugging, or an incident review. A one-off check is useful for diagnosis, but production systems need continuous monitoring once the immediate question is answered.
- 99.9% leaves minutes per day; 99.99% leaves seconds.
- A tighter SLA demands faster detection and a real escalation path.
- Maintenance and dependency risk eat into the budget too.
From one-off check to continuous monitor
Use the downtime budget to choose how fast you need to detect failures, who owns escalation, and how much redundancy your promise actually requires.
- Recreate the same check in Sandglass on an interval so the next change is caught without re-running the lookup.
- Send failures to email, a Slack webhook channel, or a generic webhook owned by whoever fixes the problem.
- Track the result over time instead of treating one manual reading as the final answer.
Why a lookup is not monitoring
An SLA is a commercial commitment, not a dashboard metric. Do not promise a number your detection speed and response process cannot defend during a real incident.
Use this tool well
Step 1: Run the check and read the result
Use the output to confirm the current state, and treat anything surprising as a starting point for diagnosis rather than a verdict.
Step 2: Define what healthy means
Write down which results count as healthy, degraded, or failed before you automate anything.
Step 3: Promote it to a continuous monitor
Recreate the same check in Sandglass on an interval so the next change is caught automatically.
Step 4: Route the alert to an owner
Send failures to email, a Slack webhook channel, or a generic webhook owned by whoever will fix them.