Practical guide
How to use the uptime calculator
The uptime calculator translates an availability percentage into an approximate amount of allowed downtime over common periods. It helps make an SLA target concrete, but it does not define how a provider measures incidents.
Good reasons to use it
- Compare the practical difference between 99.9% and 99.99% availability.
- Estimate a monthly error budget.
- Explain an SLA target to non-technical stakeholders.
A reliable workflow
- Enter the stated availability percentage.
- Review the corresponding downtime estimate.
- Read the provider’s SLA definition, exclusions and measurement window.
How to interpret the result
A percentage can be measured per month, year, region, service or request. Planned maintenance, partial degradation and dependencies may be excluded. The contractual definition controls any service credit.
Frequently asked questions
Is 99.9% the same every month?
The percentage is the same, but the allowed minutes vary with the length of the measurement period.
Does planned maintenance count?
It depends on the provider’s written SLA. Many agreements exclude specific maintenance windows.