How Much Does an Hour of Downtime Actually Cost Your Business?

If your systems went down for an hour tomorrow, what would it cost you?

Most business owners pause when we ask this question — and the number they guess is almost always too low.

Downtime costs are sneaky. They don't show up neatly on a report. They scatter across the day in ways that are easy to miss unless you actually sit down and map them out. Here's a five-minute way to get a real number you can plan around.

The back-of-the-napkin downtime calculator

You don't need a complicated spreadsheet for this. Four numbers, one formula.

1. Lost revenue

Take your annual revenue and divide it by roughly 2,000 (the approximate number of working hours in a year). That's your revenue per hour.

A business bringing in $2 million a year is looking at about $1,000 per hour. If your systems are down and you can't process orders, serve customers, or close deals, that revenue doesn't come back — it's just gone.

2. Idle employees

Count how many people can't do their jobs when systems go down, then multiply by their average hourly cost (wages plus benefits).

Ten employees at $30/hour is $300 sitting idle — every hour the outage continues.

Add this to your lost revenue number for a subtotal.

3. Recovery time

This is the piece most people miss entirely.

When systems come back online, work doesn't just snap back to normal. There's catch-up: re-entered data, figuring out what got lost, client responses that piled up while you were down. A one-hour outage rarely costs just one hour.

A reasonable rule of thumb: add 50% for recovery. Multiply your subtotal by 1.5 to get your estimated cost per downtime event.

4. Customer impact

Harder to put a dollar figure on, but often the most expensive line item.

Missed calls. Failed transactions. A prospective customer who reaches out at exactly the wrong moment and gets nothing back. What's one lost customer worth to your business over time? $5,000? $25,000? More?

Putting it together

Take a 20-person accounting firm bringing in $3 million a year:

• Lost revenue: $1,500/hour
• Idle employees (15 affected, ~$30/hour average): $450/hour
• Subtotal: $1,950/hour
• With the recovery multiplier: $2,925/hour
• Plus whatever customer relationships take a hit

That's nearly $3,000 for a single hour — before a single customer walks away.

What actually causes downtime?

"Downtime" tends to conjure up one image: a dramatic, all-systems-down outage. In reality, it's rarely that clean. Downtime is any stretch of time where your team can't do their jobs the way they normally would — and it shows up in more forms than most business owners expect.

Cyberattacks and ransomware Not just the headline-grabbing breaches. A single phishing email that locks an employee out of their account, or a piece of malware that quietly spreads across shared drives, can bring work to a halt long before anyone realizes what happened.

Hardware failure Servers, hard drives, and networking equipment all have a lifespan. When aging hardware fails — and it eventually does — recovery time depends entirely on whether backups and replacement plans were already in place.

Human error An accidentally deleted file, a misconfigured setting, a password reused one too many times. This is one of the most common causes of downtime and one of the easiest to overlook, because it doesn't feel like an "IT problem" until it becomes one.

Software and patch issues Updates are supposed to fix things. Sometimes they break something else instead. Without proper testing and staged rollouts, a routine update can take down a critical application in the middle of a workday.

Internet and network outages If your ISP goes down, or your internal network hiccups, it doesn't matter how solid your systems are — nobody can reach them. This is often outside your direct control, which is exactly why having a plan for it matters.

Power outages Storms, grid issues, or a tripped breaker. Florida businesses know this one well. Without proper backup power and failover planning, a weather event three counties away can still take your office offline.

Third-party and vendor outages Cloud platforms, payment processors, and other services you rely on can go down without any warning — and without you touching a single thing. You're still the one who has to explain it to your customers.

Insufficient or untested backups This isn't a cause of the initial outage, but it's often what turns a 20-minute problem into a 20-hour one. A backup that hasn't been tested is a hope, not a plan.

The common thread: most of these causes aren't rare, dramatic events. They're everyday risks that exist in every business, all the time, whether or not anyone is paying attention to them. That's what makes the downtime math from above worth taking seriously — it's not a "what if a meteor hits the server room" scenario. It's a "what happens on an ordinary Tuesday" scenario.

Why this number is almost always underestimated

Nobody sends you an invoice that says "here's what you didn't make while your systems were down." Lost customer revenue is even harder to trace — the customer who needed you in that moment and got silence doesn't usually call back to complain. They just quietly start looking elsewhere. There's no alert for that, no paper trail showing the exact moment you went from their go-to to one of several options.

Worth sitting with

Most businesses never run this calculation. Once you do, downtime stops looking like a minor annoyance and starts looking like what it actually is: a real, quantifiable risk sitting on your books.

So — what's your number, and are you comfortable with it?

If you're curious what your own downtime number looks like, or want a second set of eyes on where your risk actually sits, Tridium Technology Solutions is always happy to talk shop.