[{"data":1,"prerenderedAt":134},["ShallowReactive",2],{"content:\u002Ftools\u002Fhow-much-downtime-is-99-999-percent":3,"related:\u002Ftools\u002Fhow-much-downtime-is-99-99-percent,\u002Ftools\u002Fuptime-sla-calculator":126},{"id":4,"title":5,"body":6,"category":104,"description":105,"extension":106,"faq":107,"h1":5,"meta":116,"navigation":117,"path":118,"published":119,"readingMinutes":120,"related":121,"seo":123,"stem":124,"updated":119,"__hash__":125},"tools\u002Ftools\u002Fhow-much-downtime-is-99-999-percent.md","How much downtime is 99.999% uptime?",{"type":7,"value":8,"toc":93},"minimark",[9,13,17,22,25,29,42,46,49,53,56,60,69,73,81,85],[10,11,12],"p",{},"99.999% uptime, five nines, allows about five minutes of downtime in a whole year. It is the benchmark for telecommunications and critical infrastructure.",[14,15],"uptime-table",{"percent":16},"99.999",[18,19,21],"h2",{"id":20},"what-does-99999-uptime-mean-in-practice","What does 99.999% uptime mean in practice?",[10,23,24],{},"Five nines is a statement about engineering, not about monitoring. A single reboot, a DNS change or a certificate swap done slowly can break it, so every change has to be designed to happen without interruption.",[18,26,28],{"id":27},"who-is-99999-uptime-right-for","Who is 99.999% uptime right for?",[30,31,32,36,39],"ul",{},[33,34,35],"li",{},"Telecoms and emergency services",[33,37,38],{},"Core financial infrastructure",[33,40,41],{},"Large platforms with global failover",[18,43,45],{"id":44},"who-should-aim-higher","Who should aim higher?",[10,47,48],{},"Almost everyone else. Measuring five nines honestly takes checks every few seconds from several regions, and the cost of delivering it is out of proportion for any ordinary website.",[18,50,52],{"id":51},"what-does-it-take-to-reach-99999-uptime","What does it take to reach 99.999% uptime?",[10,54,55],{},"It takes redundant everything, active failover across regions, staged deploys and a team on call. Most claims of five nines are about a single component, not the experience of a visitor.",[18,57,59],{"id":58},"how-is-the-downtime-calculated","How is the downtime calculated?",[10,61,62,63,68],{},"The allowed downtime is the length of the period multiplied by the share of it you may be down: period x (100 - 99.999) \u002F 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 ",[64,65,67],"a",{"href":66},"\u002Ftools\u002Fuptime-sla-calculator","uptime and SLA calculator"," for any other percentage, or to turn the downtime you had into an uptime figure.",[18,70,72],{"id":71},"how-do-i-know-what-uptime-i-actually-deliver","How do I know what uptime I actually deliver?",[10,74,75,76,80],{},"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 ",[64,77,79],{"href":78},"\u002Fguides\u002Fhow-to-set-up-uptime-monitoring-for-client-websites","setting up uptime monitoring for client websites"," shows how.",[18,82,84],{"id":83},"where-datumboard-fits","Where Datumboard fits",[10,86,87,88,92],{},"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 ",[64,89,91],{"href":90},"#early-access","join the list below",".",{"title":94,"searchDepth":95,"depth":95,"links":96},"",2,[97,98,99,100,101,102,103],{"id":20,"depth":95,"text":21},{"id":27,"depth":95,"text":28},{"id":44,"depth":95,"text":45},{"id":51,"depth":95,"text":52},{"id":58,"depth":95,"text":59},{"id":71,"depth":95,"text":72},{"id":83,"depth":95,"text":84},"Uptime","99.999% uptime allows 5 minutes 15 seconds of downtime a year and about 26 seconds a month. See what five nines means and who actually needs it.","md",[108,110,113],{"q":5,"a":109},"5 minutes and 15 seconds per year, or about 26 seconds per month.",{"q":111,"a":112},"Do any websites really have five nines?","A few critical systems do, but most published claims describe one component, not what a visitor experiences end to end.",{"q":114,"a":115},"Can I measure five nines with a monitor that checks every five minutes?","No. A check every five minutes cannot even see an outage shorter than five minutes, which already uses the whole year's allowance.",{},true,"\u002Ftools\u002Fhow-much-downtime-is-99-999-percent","2026-10-12",4,[122,66],"\u002Ftools\u002Fhow-much-downtime-is-99-99-percent",{"title":5,"description":105},"tools\u002Fhow-much-downtime-is-99-999-percent","9w3qGiNUA85xU4zZHLLBFsf1n2ye5SYvSV1h7SqVSjk",[127,130],{"title":128,"description":129,"path":122,"category":104},"How 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.",{"title":131,"description":132,"path":66,"category":133},"Uptime 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.","Free tool",1791830036896]