Uptime
How much downtime is 99.95% uptime?
99.95% uptime allows 4 hours 22 minutes 48 seconds of downtime a year and 21 minutes 54 seconds a month. Learn who needs it and what it takes.
Updated 4 min read
99.95% uptime is the figure many cloud platforms publish for a single region of a managed service. It allows about 22 minutes of downtime a month.
| Period | Allowed downtime at 99.95% |
|---|---|
| Per day | 43 s |
| Per week | 5 min 2 s |
| Per month | 21 min 54 s |
| Per year | 4 h 22 min 48 s |
What does 99.95% uptime mean in practice?
Halving the allowance of three nines is a real step. A single manual fix that takes half an hour breaks the month, so recovery has to be automatic or very fast.
Who is 99.95% uptime right for?
- A SaaS product with paying customers
- A shop with steady daily sales
- A client site with a service agreement
Who should aim higher?
Most small client sites, where the extra cost and effort are rarely justified by what an outage costs.
What does it take to reach 99.95% uptime?
It generally calls for hosting with automatic failover or health-based restarts, checks every minute, on-call alerting and tested rollbacks.
How is the downtime calculated?
The allowed downtime is the length of the period multiplied by the share of it you may be down: period x (100 - 99.95) / 100. The table uses a month of one twelfth of a 365-day year. A contract that says "per month" may define a month differently, so check the wording. Use the uptime and SLA calculator for any other percentage, or to turn the downtime you had into an uptime figure.
How do I know what uptime I actually deliver?
You cannot promise an uptime you do not measure. Run external checks that confirm failures before alerting, keep the check history and report the real number each month. Our guide on setting up uptime monitoring for client websites shows how.
Where Datumboard fits
Datumboard shows the health of every client site next to deploys, renewals, search data and costs, so a failing site is at the top of one list. It is in early access, and you can join the list below.
Frequently asked questions
How much downtime is 99.95% uptime a month?
About 21 minutes and 54 seconds in an average month, using a month of a twelfth of a 365-day year, and 4 hours 22 minutes 48 seconds per year.
Is 99.95% uptime worth paying for?
Only if an hour of downtime costs you or your client more than the extra hosting and effort. For most small sites 99.9% is enough.
How is 99.95% different from 99.99%?
99.99% allows about a fifth of the downtime of 99.95%: 4 minutes 23 seconds a month against 21 minutes 54 seconds.
Keep reading
- UptimeHow much downtime is 99.9% uptime?99.9% uptime allows 8 hours 45 minutes 36 seconds of downtime a year and 43 minutes 48 seconds a month. See what three nines means for your site.Read
- UptimeHow much downtime is 99.99% uptime?99.99% uptime allows 52 minutes 34 seconds of downtime a year and 4 minutes 23 seconds a month. See what four nines demands and when it is overkill.Read
- Free toolUptime and SLA calculator (free)Turn an uptime percentage into the downtime it allows per day, week, month and year, or work out the uptime you actually had from minutes of downtime.Read