If your systems stopped working for an hour tomorrow, would you know what it would cost your business?
Most business owners have a rough idea. They might estimate lost sales, a few frustrated employees, or some temporary disruption. But when you dig deeper, the real figure is usually much higher than expected.
The reason is simple. Downtime affects far more than revenue. It impacts productivity, customer experience, operational efficiency, and your team’s ability to keep work moving. Many of those costs never appear on a financial report, making them easy to overlook.
The good news is you don’t need a complicated spreadsheet or finance degree to get a realistic estimate.
With a few simple calculations, you can build a clearer picture of what an outage would actually cost your organisation and whether your current level of risk is acceptable.
The Back-Of-The-Napkin Downtime Calculator
You don’t need specialist software to work this out.
A simple calculation can give you a surprisingly useful starting point.
The goal isn’t to produce a perfect number. It’s to understand the potential impact well enough to make better business decisions.
1. Lost Revenue
Start by calculating how much revenue your business generates during a typical working hour.
One simple method is to divide your annual revenue by approximately 2,000 working hours, which is roughly the number of business hours in a year.
For example, a business generating AUD $3 million annually produces roughly AUD $1,500 in revenue every working hour.
If your systems are unavailable and customers can’t place orders, book services, access information, or complete transactions, that revenue opportunity may disappear completely.
Your number: $___ per hour
2. Idle Employees
Next, consider how many employees are affected when critical systems become unavailable.
If staff can’t access applications, files, email, customer information, or cloud platforms, they’re often unable to work effectively.
Calculate the average hourly employment cost for each affected employee, including salary, superannuation, and other employment expenses.
If 10 employees cost the business approximately $50 per hour each, that’s $500 per hour in lost productivity alone.
Your number: $___ per hour
Now combine your lost revenue figure with your employee productivity cost.
Lost Revenue: $___ per hour
Idle Employees: $___ per hour
Subtotal: $___ per hour
At this point, many businesses are already surprised by the result.
3. Recovery Time
This is where downtime becomes more expensive than most people realise.
When systems come back online, work doesn’t instantly return to normal.
Employees need to catch up on delayed tasks. Customer requests need responses. Data may need to be re-entered. Projects often need to be rescheduled. Internal teams spend time figuring out what happened and what was missed during the outage.
In other words, a one-hour outage rarely creates only one hour of disruption.
A practical rule of thumb is to add 50 per cent for recovery and catch-up time.
That means a one-hour outage may actually create 90 minutes of business disruption.
Multiply your subtotal by 1.5.
Estimated Downtime Event Cost: $___
4. Customer Impact
This is often the hardest cost to measure, but it can be the most significant.
Think about what happens from the customer’s perspective during an outage.
A prospective client submits an enquiry and never receives a response.
A customer tries to place an order and can’t.
A business partner attempts to contact your team and reaches a dead end.
Most customers won’t wait indefinitely. They’ll simply move on to another option.
The challenge is that these losses often happen quietly.
You rarely receive a notification saying a customer chose a competitor because your systems weren’t available when they needed you.
Ask yourself:
What is a typical customer worth to your business over their lifetime?
$5,000?
$25,000?
$100,000?
Even a single lost relationship can dramatically change the true cost of downtime.
What Does Your Number Look Like?
Let’s look at a simple example.
Imagine a 20-person professional services firm in Melbourne generating approximately AUD $3 million in annual revenue.
Lost revenue: $1,500 per hour
Employee productivity costs: $750 per hour
Subtotal: $2,250 per hour
Applying the recovery multiplier brings the total to approximately $3,375 per downtime event.
And that’s before considering any impact on customer relationships, reputation, or future opportunities.
Suddenly, even a relatively short outage starts looking expensive.
The question becomes:
How many hours of downtime would it take before the cost exceeds what you’d invest annually to reduce the risk?
For most businesses, the answer isn’t many.
Why This Number Almost Always Gets Underestimated
Downtime is difficult to measure because the biggest costs are often invisible.
Nobody sends an invoice for lost opportunities.
Customers rarely explain that they chose a competitor because they couldn’t reach you at a critical moment.
Potential deals don’t arrive with a note saying, “This would have happened if your systems were available.”
Instead, the consequences show up gradually through lost momentum, delayed projects, reduced productivity, and missed opportunities that are impossible to fully quantify after the fact.
That’s why so many organisations underestimate the true financial impact of downtime.
They only measure what they can easily see.
You Have The Number. Now What?
Once you’ve worked through this exercise, your perspective on downtime usually changes.
It stops feeling like a minor inconvenience and starts looking like a measurable business risk.
The next question is whether you’re comfortable with that level of exposure.
If the answer is no, that’s where proactive planning becomes important.
The right technology strategy won’t eliminate every risk, but it can significantly reduce the likelihood and impact of costly disruptions.
Because when you understand what downtime is actually costing your business, investing in prevention becomes a much easier decision.
Schedule a FREE 30-minute call and we’ll walk through your number, where your biggest risks are and how we can reduce them.