Downtime Cost Calculator: What Does an Hour of IT Downtime Cost?
When a server, application or data center goes down, the first question is “when will it be back?” The second is “what did it cost us?” This downtime cost calculator estimates the cost of IT downtime per hour from lost revenue and lost staff productivity, then compares the total cost of a single incident at your current and target recovery times. The formula is laid out below, so the result is an estimate your finance team can check rather than a black box.
All calculations run in your browser; the revenue and cost figures you enter are not sent to a server.
How to Shorten Recovery Time
The difference in the result shows what each hour of recovery time is really worth. The MAV Cloud team can help define a disaster recovery setup that matches the criticality class of each system.
What is downtime cost and how is it calculated?
Downtime cost is the revenue lost for every hour IT systems are unavailable, plus the cost of staff who are idle or slowed down during that hour. The calculator adds a one-off recovery cost per incident and multiplies the hourly figure by the recovery time.
- Hourly revenue loss: annual revenue × share of revenue dependent on IT ÷ working hours per year.
- Hourly productivity loss: employees affected × hourly cost per employee × productivity loss %.
- Hourly downtime cost: the sum of the two.
- Cost per incident: hourly downtime cost × recovery time (hours) + extra recovery cost.
This follows the basic logic of the business impact analysis (BIA) described in NIST’s contingency planning guide: first determine how an outage of each system affects business processes, then define the maximum tolerable downtime based on that impact (NIST SP 800-34 Rev.1, Contingency Planning Guide).
Worked example: 24 hours versus 2 hours
With the calculator’s default values, the hourly downtime cost comes to about 24,533; a 24-hour recovery costs about 613,800 per incident and a 2-hour recovery about 74,067. The inputs below are illustrative only and do not come from any customer.
| Item | Input / calculation | Result |
|---|---|---|
| Hourly revenue loss | 50,000,000 × 60% ÷ 2,250 hours | ≈ 13,333 |
| Hourly productivity loss | 40 employees × 400 × 70% | ≈ 11,200 |
| Hourly downtime cost | 13,333 + 11,200 | ≈ 24,533 |
| Current recovery (24 hours) | 24,533 × 24 + 25,000 | ≈ 613,800 |
| Target recovery (2 hours) | 24,533 × 2 + 25,000 | ≈ 74,067 |
| Difference per incident | 613,800 − 74,067 | ≈ 539,733 |
The calculator is currency-agnostic: results come out in whatever currency you enter. The last row is the direct cost avoided per incident by shortening recovery time.
Where should each input come from?
Most inputs come from finance and HR records; IT dependency and recovery time come from business units and the IT team together. Note the source of each input before presenting the result to management.
Annual revenue comes from the income statement of the last closed financial year. Working hours per year are the hours the business actually operates: 2,250 for an organization working 250 days at 9 hours a day, and much higher for an online store that sells around the clock. Hourly cost per employee should be the full employer cost, not just gross salary.
Productivity loss is high for roles that depend entirely on a system, such as ERP or contact-center software, and lower for work that can continue on paper or offline. Extra recovery cost covers one-off items such as overtime, outside support and emergency hardware.
How does IT dependency vary by type of business?
The share is high where revenue is generated directly through systems and lower where work can continue manually for a while. The right figure comes from your own revenue streams, not from an industry average.
In e-commerce, online booking, payment services and SaaS products, every order or transaction runs through the system, so an outage is a direct loss of sales. In manufacturing, when shipping, planning and invoicing depend on ERP, the business impact of downtime grows within hours. In professional services, lost revenue usually shows up as deferred work, so the productivity line carries more weight.
How do RTO and RPO drive the cost of downtime?
RTO (Recovery Time Objective) is the maximum acceptable time for a system to be running again after an outage; the calculator’s recovery time field corresponds directly to it. RPO (Recovery Point Objective) is the maximum acceptable data loss, measured as the time since the last recovery point.
The link between RTO and cost is linear: with a fixed hourly downtime cost, each extra hour of recovery adds the same amount. RPO is not part of the calculator, but it raises cost in a different way. Lost orders or transactions take time to re-enter, and some data cannot be recovered at all.
The Right RPO and RTO for Critical Systems
Not every system needs the same recovery target. Classifying by criticality puts investment where downtime costs most.
Which recovery approach does the result point to?
Systems with a high hourly downtime cost justify approaches that deliver short recovery times; systems with a low cost can use more economical ones. Restore from backup, replication and disaster recovery as a service (DRaaS) are the three main points on that range.
Restore from backup has the lowest running cost, but restore time grows with data volume; it often suits supporting systems. Periodic or continuous data replication keeps data current at a second location, reducing both data loss and the time needed to switch over.
In a DRaaS model, replication, standby infrastructure and the failover process are managed together by the provider. Systems that show a large difference in the calculator are the first candidates for this approach. Which method delivers which recovery time is determined per project.
How do you build the business case?
A downtime cost calculator result is most often used in the business case, which compares the annual cost of a disaster recovery solution with the cost it avoids across expected outage incidents. The calculator’s difference per incident is the core input for that comparison.
Three questions matter: how many incidents are expected per year, how many affect critical systems, and how much the solution shortens recovery? Your own incident history is the most reliable source. It is also worth showing a separate scenario for a single major event, such as a ransomware attack or a data center failure, which can outweigh years of spending on the solution.
Why is a business impact analysis more than a calculator?
A business impact analysis shows not only what an outage costs, but which systems each business process depends on and how long each process can be down. The calculator is the financial summary; process maps, dependencies and priorities still need to be worked out.
This logic also appears in ISO 22301, the business continuity management system standard. The outputs feed directly into a disaster recovery plan.
Common mistakes when calculating downtime cost
- Lumping all systems together: email and ERP do not cost the same when they go down; calculate critical systems separately.
- Being optimistic about recovery time: a system being online is not business back to normal; validation and backlog count too.
- Using gross salary only: leaving out employer costs makes productivity loss look smaller than it is.
- Forgetting what the calculator leaves out: reputational damage, contractual penalties and SLA credits owed to your own customers, regulatory consequences of data loss (such as under data protection law) and lost future customers are not included; the real cost is usually higher.
Disaster recovery at MAV Cloud: recovery targets and support
In MAV Cloud’s disaster recovery service, RPO and RTO targets are defined for each project according to the criticality class of the systems. Critical systems get continuous replication and priority failover, important systems periodic replication, and for supporting systems restore from backup may be enough. The calculator’s result gives a concrete starting point for that classification.
Disaster recovery services are covered by MAV Cloud’s service level agreement, with first-response targets of 15 minutes for critical, 1 hour for high, 4 hours for medium and 1 business day for low priority.
MAV Cloud is certified to ISO 22301 for business continuity management and ISO/IEC 27001 for information security management (see our certifications).
Frequently Asked Questions
How do I calculate downtime cost?
Multiply annual revenue by the share that depends on IT and divide by working hours per year, then add affected employees × hourly cost × productivity loss. Multiply that hourly figure by the recovery time and add any one-off recovery cost.
How accurate is the calculator?
It is only as good as the inputs and covers direct costs only, so the real cost is usually higher.
What is the difference between RTO and RPO?
RTO is the maximum acceptable time for a system to be running again. RPO is the maximum acceptable data loss, measured as the time since the last recovery point.
Is anything I enter stored?
No. The calculation runs in your browser, and revenue and cost figures are not sent to a server.
Turn the Calculated Risk Into a Recovery Plan
Share your critical systems and current backup setup, and the right recovery approach and targets for your downtime cost can be worked out together.
If the figures are still rough, use the calculator to compare scenarios; if critical systems are clear, the quote link on the result screen is the fastest route.