Uptime SLA Calculator
Allowed downtime for each SLA level.
Enter your values
Enter the uptime target in %.
Enter the actual downtime this month in min.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Allowed per month
- 21.9 min
- Allowed per year
- 4.38 hours
- Allowed per day
- 0.72 min
- SLA status
- SLA breached
Quick answer
An uptime SLA sets the maximum downtime allowed over a period.
Downtime = period × (1 − uptime %)
At a glance
| What it does | Allowed downtime for each SLA level. |
|---|---|
| Category | Technology |
| Inputs needed | Uptime target, Actual downtime this month |
| Main output | Allowed per month |
| Formula | Downtime = period × (1 − uptime %) |
| Cost | Free — no sign-up, no download |
How to use the Uptime SLA Calculator
- 1Enter your uptime target percentage.
- 2Enter actual downtime recorded.
- 3Compare against the monthly allowance.
Inputs explained
- Uptime target(%)
- Enter the uptime target in %.
- Actual downtime this month(min)
- Enter the actual downtime this month in min.
Worked example
Using the values the calculator loads with:
Inputs
- Uptime target99.95 %
- Actual downtime this month35 min
Results
- Allowed per month21.9 min
- Allowed per year4.38 hours
- Allowed per day0.72 min
- SLA statusSLA breached
Frequently asked questions
What is three nines?
99.9% uptime, about 43 minutes downtime per month.
Does planned maintenance count?
Usually excluded if the SLA defines a maintenance window.
What do I need to enter into the Uptime SLA Calculator?
Just 2 values: uptime target, actual downtime this month. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Uptime SLA Calculator work out the answer?
An uptime SLA sets the maximum downtime allowed over a period. It applies the formula Downtime = period × (1 − uptime %) and shows the working so you can check each step by hand.
Is the Uptime SLA Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.