Free Tool
Downtime Cost Calculator
Most site owners underestimate what downtime costs because they only count the sales that did not happen. An outage also burns staff hours on detection, firefighting, and client management. Put your own numbers in to see the real figure.
30 minutes of downtime at your numbers costs an estimated $7 in lost revenue.
How this is calculated
Revenue per minute = monthly revenue ÷ (30 × 24 × 60), i.e. revenue spread evenly across a 30-day month.
Direct revenue lost = revenue per minute × downtime minutes.
Staff cost (if included) = staff count × hourly rate × hours spent.
Total estimated cost = direct revenue lost + staff cost, rounded to whole dollars. Real losses vary with when the outage happens and how concentrated your revenue is; treat this as a floor, not a ceiling.
How it works
Three steps, no signup.
Everything runs in your browser. Nothing you type is sent to a server or stored.
Enter your numbers
Put in the monthly revenue this site brings in and how long it was down, or might be. Optionally add the staff time an outage burns on detection and firefighting.
We do the math in your browser
We spread revenue evenly across a 30-day month to get a per-minute rate, multiply by the downtime, and add staff cost if you included it. Nothing is sent anywhere.
See the real figure
You get the estimated cost of that outage, split into lost revenue and staff time. Treat it as a floor, not a ceiling: it leaves out SEO, reputation, and wasted ad spend.
For agencies
It multiplies across the portfolio.
For agencies, the number above multiplies across every site in the portfolio, and the client relationship absorbs the damage before the invoice does. A client who discovers their own outage before you do starts wondering what else you are missing, which is how churn conversations begin. If your contracts include uptime commitments, an unnoticed outage can also put you in breach of an SLA you did not know you were violating. And there is a reputational cost that never shows up in a formula: it is real, it compounds, and it is the hardest one to win back.
Go deeper
How do you calculate the cost of downtime?
We spread your monthly revenue evenly across a 30-day month to get revenue per minute, then multiply by the minutes of downtime. If you include staff time, we add the number of people times their hourly rate times the hours spent. The two figures together are the estimate.
What counts as monthly revenue for this?
Use the revenue you can attribute to this specific site: online sales, bookings, ad revenue, or leads that convert. If the site is not directly transactional, estimate the share of revenue it supports.
Why is this described as a floor, not a ceiling?
It only counts direct lost revenue and staff time. It leaves out the costs that are real but hard to price: SEO damage, wasted ad spend, lost customer trust, and SLA penalties. Your true cost is usually higher.
How do I lower the cost of an outage?
Most of the staff-time cost is the gap between an outage starting and someone noticing. Monitoring shrinks that gap to the length of an alert, which is where Sentinel comes in.
Downtime you know about costs less
The staff-time half of your estimate starts the moment an outage begins and nobody knows. Monitoring shrinks it to the length of an alert.