Uptime Availability
Calculator
Results
- Downtime per year (minutes)
- 525.599999
- Downtime per year (hours)
- 8.759999
- Downtime per month (minutes)
- 43.799999
- Downtime per day (seconds)
- 86.399999
Computing results
| Downtime per year (minutes) | 525.599999 |
| Downtime per year (hours) | 8.759999 |
| Downtime per month (minutes) | 43.799999 |
| Downtime per day (seconds) | 86.399999 |
formula-map diagram
- Downtime per year (minutes)
- 525.599999
- Downtime per year (hours)
- 8.759999
- Downtime per month (minutes)
- 43.799999
- Downtime per day (seconds)
- 86.399999
Computing relationship
Formula
downtime = (1 − availability) × period= 525.59999999994
Note
This is a simplified model: it applies the standard computing formula to the numbers you entered and ignores protocol overhead, compression variability, retries, contention and other real-world effects. Size your systems with measured data.
More in Technology and computing
See all →Frequently asked questions
What does an availability percentage like 99.9% actually mean?+
It represents the fraction of total time a system is expected to be operational, expressed as a percentage. This calculator converts that percentage into a concrete amount of allowed downtime over a chosen period, such as a year or a month, which is often far less time than people intuitively expect.
Why does going from 99% to 99.99% make such a big difference?+
Each additional 'nine' reduces allowed downtime by roughly a factor of ten. Going from 99% (about 3.65 days of downtime per year) to 99.9% (about 8.7 hours) to 99.99% (about 53 minutes) requires disproportionately more engineering effort and redundancy for each step.
Is this the same as a Service Level Agreement (SLA) guarantee?+
This calculator shows the mathematical relationship between a percentage and downtime, which is exactly what SLAs use, but an actual SLA also defines what counts as downtime, how it's measured, and what remedies apply if the target is missed — details this calculator does not cover.
Does downtime include planned maintenance?+
That depends on how the availability figure is defined by the provider or system in question. Some SLAs exclude scheduled maintenance windows from the downtime calculation, while others count all unavailability, planned or not — check the specific definition being used for your number.
How is this useful when choosing a hosting provider or service?+
Converting an advertised availability percentage into hours or minutes of allowed downtime per year makes it much easier to judge whether that level of reliability is acceptable for your use case, rather than comparing abstract percentages that look deceptively similar.