Free tool

SLA calculator

Enter an uptime target to see how much downtime it allows per day, per week, per month and per year.

Target uptime (%)

Per day: 1 min 26 s
Per week: 10 min 5 s
Per month: 43 min 50 s
Per quarter: 2 h 11 min
Per year: 8 h 45 min

Allowed downtime by target

The most common targets, calculated on a 365-day year and an average month of 30.44 days.

Target	Per day	Per week	Per month	Per quarter	Per year
99 %	14 min 24 s	1 h 40 min	7 h 18 min	21 h 54 min	3 d 15 h
99.5 %	7 min 12 s	50 min 24 s	3 h 39 min	10 h 57 min	1 d 19 h
99.9 %	1 min 26 s	10 min 5 s	43 min 50 s	2 h 11 min	8 h 45 min
99.95 %	43 s	5 min 2 s	21 min 55 s	1 h 5 min	4 h 22 min
99.99 %	9 s	1 min	4 min 23 s	13 min 9 s	52 min 34 s
99.999 %	1 s	6 s	26 s	1 min 19 s	5 min 15 s

SLA, SLO and SLI

The SLA is your contractual commitment to your customers, the SLO is the internal target you set yourself, and the SLI is the actual measurement, such as the percentage of successful checks.

Each extra "9" cuts downtime by ten

Going from 99.9% to 99.99% brings allowed monthly downtime down from about 44 minutes to about 4 minutes.

Measure it to prove it

An SLA is only worth something if it is measured: external monitoring from multiple regions gives you real, verifiable uptime.

Questions

SLA FAQ

What does 99.9% uptime mean?

The service can be unavailable 0.1% of the time, which is about 43 minutes per month or 8 hours 45 minutes per year.

What SLA should I offer my clients?

99.9% is common for a website or SaaS hosted on a single infrastructure; 99.99% requires redundancy and a responsive on-call team.

How do I measure my actual uptime?

With external monitoring such as LucidStack: each monitor has an uptime target and reports show the measured uptime.

Does maintenance count?

It depends on your contract. In LucidStack, scheduled maintenance windows are excluded from the calculation.

Status pages On your own domain, with subscribers, history and a backup copy. Learn more Client reports A monthly PDF report per client, in your brand colors. Learn more Website monitoring Uptime, response time and certificates for your websites, checked from three countries. Learn more Multi-region monitoring Paris, Amsterdam and Warsaw, with outages confirmed by majority. Learn more

Start monitoring in two minutes.

Add a URL, choose where to be alerted. LucidStack takes care of the rest, day and night.

Create my free account Explore the features