How much does website downtime cost?
Website downtime costs your monthly revenue divided by 43,200 (the minutes in a 30-day month) for every minute you're offline, plus indirect costs like abandoned carts, support load and lost customers. For a small business that's usually dollars or hundreds of dollars a minute; the thousands-per-minute figures in the press come from studies of large enterprises.
The real cost of website downtime compares the published studies: Splunk's 2026 report puts the Global 2000 average at about $15,000 a minute, while ITIC's small-business worked example lands at about $417 a minute. Your own number, worked out from your own revenue, is the one worth planning around, which is what the calculator above does.
How does the calculator work it out?
- Revenue per minute. Monthly revenue ÷ 43,200.
- Indirect costs. That figure is multiplied by an industry factor, from 1.1× for education to 3× for finance. These factors are the calculator's own assumptions, not published figures, and the result says so.
- Orders lost. Monthly revenue ÷ average order value gives your orders per hour, so you can see how many sales an hour offline costs.
- Yearly exposure. Your hosting's uptime promise sets the worst-case downtime per year. Without failover, the calculator assumes 50% more.
Worked example
For this example, assume an online store making $50,000 a month on hosting with a 99.9% uptime promise and no failover:
| Step | Result |
|---|---|
| Revenue per minute ($50,000 ÷ 43,200) | $1.16 |
| With the 1.5× e-commerce factor | $1.74 a minute, about $104 an hour |
| Worst-case downtime (526 minutes a year × 1.5 without failover) | About 788 minutes a year |
| Yearly revenue at risk | About $1,369 |
That's the number to weigh against better hosting or monitoring: if an upgrade costs less than the exposure it removes, it pays for itself.
What does an uptime percentage actually allow?
Uptime promises sound close together, but the downtime they allow isn't. These are straight arithmetic on the 525,600 minutes in a year:
| Uptime | Downtime allowed per year |
|---|---|
| 99% | About 87.6 hours |
| 99.9% | About 8.8 hours |
| 99.95% | About 4.4 hours |
| 99.99% | About 53 minutes |
An SLA is a ceiling, not a forecast. Many hosts do better than their promise, so the calculator's yearly figure is a worst case.
Why does downtime cost more than lost sales?
The revenue you'd have made during the outage is only the visible part. Ads keep sending paid traffic to an error page, support tickets pile up, and some customers who hit the error never come back: in Splunk's 2026 survey, 81% of technology leaders said downtime had cost them customers. Stores feel it most, because a broken checkout loses sales even when the rest of the site loads. E-commerce downtime cost covers that case.
How do you reduce the cost of downtime?
- Find out faster. Every minute between an outage starting and someone noticing is pure loss. Uptime monitoring tools compared covers free options that check every few minutes.
- Prevent the common causes. Traffic spikes on undersized hosting, DNS mistakes and expired domains, plugin conflicts, expired SSL certificates and untested changes are all preventable. What causes website downtime covers each one with its fix.
- Right-size your hosting. If you've outgrown shared hosting, the hosting cost calculator shows what the next tier costs.
- Tell customers what's happening. Clear updates cut support load. We've written outage messages you can copy.
- Plan migrations properly. A staged cutover keeps planned downtime to minutes; see how long WordPress migration downtime lasts.
