Skip to content
Allin
Sign up · Sign in

Uptime / SLA calculator

Turn an uptime percentage into allowed downtime per year, month and day.

Related tools

All Data & computing tools →
Data usage calculatorEstimate your monthly data usage from hours of activity per day.ASCII Table ReferenceFull ASCII table (0-127) with a decimal / hex / octal / binary / character converter and a text-to-codes panel.Aspect ratio calculatorFind the aspect ratio of any width and height, like 16:9.Audio file size calculatorEstimate an uncompressed audio file's size from its length, sample rate and bit depth.Bandwidth CalculatorEstimate the internet speed your household needs.Bitrate CalculatorCompute the bitrate of a media file from its size and duration.Citation Generator (APA / MLA / Chicago)Generate a correctly formatted reference-list entry and in-text citation (or footnote) in APA 7, MLA 9 or Chicago 17 for websites, books, journal articles and newspapers, with one-click copy.Cron expression generatorBuild a cron schedule field by field — minute, hour, day of month, month, weekday — and see the expression and a plain-language description update live. One-click presets cover the common schedules, and the syntax (*, */5, 1-5, 1,15) is explained inline.

Need Downtime/year (min), Downtime/month (min), Downtime/day (sec)? The Uptime / SLA calculator derives it from Uptime (%) in one step. For instance, with Uptime (%) = 99.9 it returns Downtime/year (min) = 525.6, Downtime/month (min) = 43.8 and Downtime/day (sec) = 86.4.

How to use it

  1. Enter your values: Uptime (%).
  2. Read the result instantly: Downtime/year (min), Downtime/month (min), Downtime/day (sec).

Frequently asked questions

What does the Uptime / SLA calculator actually compute?

It takes Uptime (%) and derives Downtime/year (min), Downtime/month (min) and Downtime/day (sec) from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

A single value: Uptime (%). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Uptime (%) = 99.9, the calculator returns Downtime/year (min) = 525.6, Downtime/month (min) = 43.8 and Downtime/day (sec) = 86.4. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Uptime (%) = 199.8 instead, Downtime/year (min) goes from 525.6 to -524,549 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Uptime (%) = 49.95, Downtime/year (min) comes out at 263,063. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Finding out how big a thing will be before you make it: how many gigabytes an hour of footage takes, how long a file needs on the connection you have, how large a photo prints before it goes soft, what bitrate fits the budget you were given.

What is the most common mistake?

Taking the advertised connection speed as the transfer speed. A 100 Mb/s line is megabits, the file is in megabytes, and the eight-fold difference between them is where most download estimates go wrong — before overhead and contention take their own share.

What is the difference between the Uptime / SLA calculator and the Data usage calculator?

This one returns Downtime/year (min) and Downtime/month (min); the Data usage calculator returns Total data (GB). That is the whole difference — open the one whose figure you need.

Where do the figures come from, and how current are they?

Byte prefixes follow the IEC convention where a kibibyte is 1 024 bytes and a kilobyte is 1 000 — drive makers use the second, operating systems often report the first, and a disk that shrinks on arrival is that gap and nothing else. Print sizing assumes 300 dpi unless you change it.

Further reading

All guides →
ExplainerWhat an Availability Percentage Actually AllowsThree nines sounds like a promise until you divide it into minutes. What 99.9 % buys per year, per month, per week and per day; why the measurement window matters far more than the extra nine; and the two different months this tool uses for the same slug.ExplainerWhat Is Bitrate? Bits per Second, CBR vs VBRBitrate is how many bits of data a video or audio stream uses each second. Learn how it sets quality and file size, and the difference between constant and variable bitrate.ExplainerHow Much Data Streaming Uses: SD, HD, and 4K per HourSee how many gigabytes per hour SD, HD, and 4K video use, and how to check a monthly streaming habit against a data cap.How-toHow Much Internet Speed Do You Need? A Household GuideWork out the internet speed your home needs by adding up Mbps per video stream, video call, and gamer, with clear examples.How-toHow to Write a Cron Expression: Five Fields and the OR Rule Nobody MentionsMinute, hour, day of month, month, day of week. The traps are that a step is a stride through a range and not an interval, and that the two day fields are combined with OR — so 0 0 1 * 1 fires on the 1st and on every Monday.ExplainerHow Unix File Permissions Work: Reading 755 Without GuessingRead is 4, write is 2, execute is 1, and each of the three digits describes a different party. The part most explanations get wrong is what the execute bit does on a directory — it grants traversal, not the right to run anything.