# What "99.9% uptime" really means (and what to ask instead) Source: https://dijihost.co.uk/guides/what-99-9-uptime-means/ Updated: 2026-10-18 > A 99.9% uptime guarantee allows up to 8.76 hours offline a year, or about 43 minutes a month, and usually pays out only small account credit. Better questions are what is monitored, who is woken up and whether they can fix it. dijihost monitors around the clock and offers fully managed hosting at £1 a day + VAT. ## Key facts - A year has 8,760 hours, so 99.9% uptime allows 8.76 hours of downtime: about 8 hours 46 minutes. - Measured monthly, 99.9% of a 30-day month allows about 43 minutes offline. - 99% allows 87.6 hours a year; 99.99% allows about 52.6 minutes; 99.999% about 5.3 minutes. - Uptime guarantees usually exclude planned maintenance, your own code, attacks and DNS problems. - Many uptime clauses cover only the web server, not email. - SLA credits are worked out from your hosting fee and usually have to be claimed. - dijihost does not quote an uptime percentage; its servers are monitored 24/7 and the director handles out-of-hours problems. ## The arithmetic, shown properly Almost every hosting company promises 99.9% uptime. Written down, it reads like a promise never to be offline. Do the sums and it is a promise to be offline for up to eight and three quarter hours a year, at a moment nobody consults you about. That is not aimed at anyone in particular. Real servers have bad days, ours included. The problem is that the figure has stopped carrying information, because everybody quotes it and hardly anybody defines it. A year is 365 days. Times 24, that is 8,760 hours. One tenth of one per cent of 8,760 hours is 8.76 hours, or eight hours and about forty-six minutes. Across the figures you see quoted: | Uptime | Downtime allowed per year | Per 30-day month | | 99% | 87.6 hours (three and a half days) | 7.2 hours | | 99.5% | 43.8 hours (nearly two days) | 3.6 hours | | 99.9% | 8.76 hours | about 43 minutes | | 99.99% | about 52.6 minutes | about 4.3 minutes | | 99.999% | about 5.3 minutes | about 26 seconds | Each extra nine divides the allowance by ten, which is why the jump from three nines to four is a big deal in the machine room and a small one on the sales page. Most contracts measure by the month, which flatters the number. Lose 43 minutes in March and another 43 in April, and the guarantee has been met both times while you have lost an hour and a half of trading. ## What the host counts as being down The percentage only applies to whatever the contract defines as an outage. Typical carve-outs include planned maintenance windows, anything caused by your own code or plugins, network problems belonging to somebody else, attacks, and anything to do with your domain or DNS. Strip all that out and the guarantee often covers a narrower slice of reality than you imagined. Measurement matters just as much. "Up" usually means the server answered a request from a monitoring station. Your site can answer that request while: - the database has fallen over and every page shows an error - the shopping basket is broken - the page takes thirty seconds to load and the visitor has gone back to Google All three count as up, and all three mean you are shut. Email catches people out too: a great many uptime clauses cover the web server only, so mail can stop flowing for a morning without denting the figure at all. ## The refund is not worth chasing Service level agreements pay out in account credit, worked out against what you pay. The same maths applies to us: at **£1 a day + VAT**, four hours of downtime is worth about 17p of your money. On a budget plan costing a few pounds a month, the same four hours is worth a penny or two. Some hosts multiply the credit, and ten times almost nothing is still almost nothing. Nobody is made whole by an SLA credit. The cost of a morning offline has nothing to do with the size of your hosting bill, which is why the credit is the least interesting clause in the contract. Credits are rarely automatic either. You generally have to notice the outage yourself, keep evidence and submit a claim inside whatever window the terms set. Most people never bother. ## Five questions that tell you more than a percentage ### 1. What exactly are you checking, and how often? Pinging a server proves the machine has power. Loading a real page, checking the words on it are the right words and confirming mail is moving proves the business is open. Ask which they do, and how many minutes pass between checks. ### 2. Where does the alarm go at three in the morning? "Round-the-clock monitoring" can describe a graph nobody looks at until nine. Ask whether the alert wakes a human, and which one. Ours is watched around the clock, and out of hours the alert reaches the person who would deal with it during the working day. ### 3. Is that person allowed to fix it? Plenty of first-line staff can only log a ticket and escalate. If the person who answers cannot get onto the server, the clock keeps running while your problem travels up a chain. ### 4. What happens when the fault is mine? Sites break because of a plugin update far more often than because a data centre catches fire. A budget host may say the server is fine and close the ticket. A managed host treats a broken site as a broken site. That is how we run [WordPress hosting](https://dijihost.co.uk/wordpress-hosting/), because a customer who cannot buy anything does not care whose fault it is. ### 5. How many other sites share my server? Few hosts publish this. A vague answer is still informative: packing thousands of sites onto one box is how ultra-cheap prices get built, and how your Tuesday gets ruined by somebody else's traffic spike. ## What we say instead of a number We do not publish an uptime percentage or an SLA figure. We have run our own servers since dijitul was formed in 2006, and things still go wrong occasionally, because that is what hardware and software do. So rather than paint a percentage on the wall, we tell you what happens on a bad day: somebody notices before you do, that somebody can log straight into the machine, and you can ring **01623 650333** and get a person who already knows your setup. Out of hours, that is Olly, our director. Put the five questions to your current host first. If the replies leave you uneasy, put them to us and compare. Monitoring is part of [Complete Hosting](https://dijihost.co.uk/complete-hosting/) at £1 a day + VAT, and we will happily walk you through what gets watched and who gets woken up. ## FAQs ### How much downtime does a 99.9% uptime guarantee allow? A year contains 8,760 hours, and one tenth of one per cent of that is 8.76 hours. So a 99.9% guarantee permits roughly eight hours and forty-six minutes offline per year without the host breaking its promise. Measured monthly, it works out at about 43 minutes in a 30-day month. ### Is a 99.9% uptime guarantee good? It is an ordinary target rather than an impressive one, because nearly every host quotes it. What matters more is the definition underneath: what the host counts as downtime, what it excludes, how it measures, and what it does when your site breaks for reasons that are not the server. Those answers vary enormously. ### What do I get if my host misses its uptime guarantee? Usually account credit worked out from your monthly fee. On a cheap plan, several hours offline can be worth a few pence. Credits are rarely paid automatically, so you normally have to notice the outage, gather evidence and claim within a set window. Treat the guarantee as a statement of intent rather than insurance. ### Does uptime monitoring include email? Often not. Many uptime clauses cover the web server alone, so mail can stop for hours without affecting the published figure. If email matters to your business, ask whether it is monitored, what is checked, and who is alerted when delivery stops. A good host will answer that plainly. ### Does dijihost offer an uptime guarantee? No. dijihost does not publish an uptime percentage or SLA. Instead, servers are monitored around the clock, problems out of hours are handled personally by the director, and the people who answer the phone can log into the server and fix it. Fully managed hosting costs £1 a day + VAT. ## Pricing and ordering dijihost Complete Hosting is £1 a day + VAT (£365 a year + VAT). Order at https://clients.dijitul.uk/order or call 01623 650333.