What does an uptime percentage mean in minutes?
A percentage of a month. The arithmetic is the whole point, so here it is for a 30-day month and a 365-day year:
| Uptime | Downtime allowed per month | Per year |
|---|---|---|
| 99.99% | 4.3 minutes | 52.6 minutes |
| 99.95% | 21.6 minutes | 4.4 hours |
| 99.9% | 43.2 minutes | 8.8 hours |
| 99.5% | 3.6 hours | 43.8 hours |
| 99% | 7.2 hours | 3.7 days |
A host that promises 99.9 percent and delivers exactly that can be down for most of an hour every month without breaking its word. That is fine for a brochure site and expensive for a store on a sale day.
What does the guarantee actually promise?
A credit, not uptime. Every guarantee we have read is a schedule of what the host gives back when it misses the number, and the schedules differ more than the headline percentages do. From the terms we read on 13 October 2026:
- Hosting.com credits 5 percent of the monthly fee for every hour of unscheduled downtime caused by its network or equipment, up to the full month, on request.
- FastComet credits 10 percent of the monthly fee per hour of downtime, up to 100 percent.
- SiteGround gives a 5 percent service-extension credit for a month below 99.9 percent.
- Hostinger credits 5 percent of that month’s fee, claimed within 30 days.
- Bluehost issues at most one coupon a month for 5 percent of the monthly hosting fee under its 99.99 percent SLA.
- ScalaHosting scales the credit from 10 percent at 99.8 percent to 100 percent below 99 percent, claimed through billing.
- Flashcloud starts credits at 10 percent below 99.9 percent per calendar month.
- InMotion commits to 99.99 percent on Power and Pro with credits described in its own blog; the Launch plan carries no guarantee line.
- HostPapa (shared plans) states 99.9 percent without a credit schedule in its terms.
A credit of 5 percent of a $10 plan is 50 cents. The guarantee is a signal of what the host is willing to be held to, not compensation.
What do the exclusions take away?
Usually scheduled maintenance, attacks, upstream network failures, and anything attributable to your site or your account. Several terms also exclude downtime shorter than a threshold or require that you report it within a window. Read the exclusions before the percentage: a 99.99 percent guarantee that excludes maintenance and requires a claim within seven days is weaker than a 99.9 percent one with automatic credits.
How do you know whether a host meets its number?
Measure, or read someone who did. Monitoring services check a site from outside the host’s network at a fixed interval and record every failed check; a year of 30-second checks is a strong record, a month of five-minute checks is a weak one. Our reviews list the published measurements for each host with the tool, interval, plan and window, and the numbers are instructive: of the hosts with year-long independent monitors, results run from 99.80 percent (FastComet, Mumbai account) to 99.99 percent (Hosting.com, Singapore account; ScalaHosting). The 99.80 figure would have earned credits in several months under FastComet’s own schedule.
When HostIdea’s own windows open, uptime will be measured every 60 seconds and reported monthly with the outage count, and the uptime sub-score maps 100 percent to 10 and 99.9 percent to 7.
Should the guarantee influence your choice?
A little. Prefer a host whose terms spell out a credit schedule over one that does not, because the schedule is the only part that binds. Then weigh measured uptime from a long window above any guarantee, and remember that the difference between 99.9 and 99.99 percent is 39 minutes a month, which matters only if those minutes land on your busiest hour.