Uptime Calculator

Your hosting provider promises 99.9% uptime. Sounds good. But what does it actually mean for your website? This calculator converts uptime percentages into real downtime figures: minutes per day, hours per month, days per year. Type in your SLA figure and see exactly what you’re agreeing to before you sign up.

What Do These Numbers Actually Mean?

Uptime percentages are one of those figures that sound precise until you think about what the gap represents. The difference between 99.9% and 99.99% is one decimal place on paper. In practice, it’s the difference between 8.7 hours of downtime per year and 52 minutes.

Here’s the full breakdown for the most common SLA tiers:

For most small business sites and blogs, 99.9% is the realistic baseline. It’s what the majority of shared hosting providers promise, and for sites that don’t process transactions around the clock, 8.7 hours of downtime spread across a year is manageable. For a WooCommerce store or a site that generates revenue every hour it’s online, 99.99% is worth paying for.

What Is an SLA and What Does It Actually Cover?

An SLA, or Service Level Agreement, is a contractual commitment from your host about the minimum level of service you’ll receive. In hosting, that usually means an uptime guarantee expressed as a percentage.

The important thing to understand is what an SLA does and does not give you. It guarantees compensation if uptime falls below the stated level. It does not prevent downtime from happening. A host with a 99.9% SLA that goes down for two hours has breached their SLA and owes you a credit. But your site was still down for two hours.

Credits are typically small: a few days of free hosting, sometimes a proportional refund of your monthly fee. Compensation rarely reflects the actual cost of downtime for a business. The SLA matters most as a signal of how seriously a host takes its infrastructure, not as financial protection against losses.

Most SLAs also exclude planned maintenance windows. A host that takes their servers down every Tuesday night for updates isn’t counting that against their 99.9% figure. Check the terms for how maintenance is handled before drawing conclusions from the headline number.

Does Uptime Affect Your SEO?

Yes, in two ways. When Googlebot visits your site to crawl and index your pages, it expects the server to respond. If your site is down at that moment, Googlebot logs a server error and moves on. A single missed crawl isn’t a problem. Repeated downtime during crawl windows is, because Google starts to see your pages as unreliable and may reduce crawl frequency or let rankings slip.

The second effect is indirect: slow or unreliable hosting increases your Time to First Byte, which is a direct input into Largest Contentful Paint, one of Google’s Core Web Vitals. A host that’s frequently struggling to respond quickly under load affects your performance scores, which affects rankings. Uptime and speed are connected at the infrastructure level.

Which Hosts Offer the Best Uptime Guarantees?

Here’s how four of the most reviewed providers on TSH stack up on their stated SLA:

A stated SLA is only as useful as the host’s track record. Third-party uptime monitoring services consistently show that actual uptime often falls slightly short of the advertised figure for budget shared hosts, while premium managed WordPress hosts tend to match or exceed their guarantees. Worth checking independent monitoring data before committing to any provider.

Frequently Asked Questions

What does 99.9% uptime mean?

It means your site is expected to be online for 99.9% of the time, allowing for a maximum of 43 minutes and 49 seconds of downtime per month, or 8 hours and 45 minutes per year. This is the standard guarantee offered by most mainstream shared and managed WordPress hosts.

What is the difference between 99.9% and 99.99% uptime?

The difference is roughly 8 hours of downtime per year. At 99.9%, your maximum allowable downtime is 8 hours 45 minutes per year. At 99.99%, it’s 52 minutes. For sites processing transactions or running services where timing matters, that difference has real commercial value.

What happens if my host breaches their SLA?

Most hosts offer service credits when they fail to meet their stated uptime guarantee. The credit amount varies by provider: typically a few days of free hosting or a percentage of your monthly fee. Credits are applied to your next invoice automatically in most cases, but you may need to open a support ticket to claim them. Check your host’s terms for the specific compensation structure.

Does planned maintenance count toward downtime?

Usually not. Most hosting SLAs exclude scheduled maintenance windows from their uptime calculations. This means a host can take their servers offline for planned updates without it counting against the 99.9% figure. The relevant terms are typically in the acceptable use or SLA section of your hosting agreement.

What uptime should I look for in a hosting plan?

For a blog or informational site, 99.9% is fine. For an online store, a booking system, or any site where downtime directly costs money, look for 99.99% and check the host’s actual track record in independent monitoring reports. The SLA is the floor, not the ceiling.