Cost per 8 hours
A business day down is not a calendar day down.
Eight hours covers a full shift or business day — the window that matters most for teams whose customers and operations run on business hours rather than a 24-hour clock. Model it below.
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Business day framing
Eight hours of exposure, not twenty-four.
For B2B tools, internal systems, and support operations, the meaningful outage window is often the working day, not the calendar day. An outage that starts at 5pm and clears by 9am next morning is technically 16 hours — but zero business hours.
Cost per 8 hours
Cost per hour multiplied by 8 — the baseline for a full shift or business day fully down.
Business-hours discount
If an outage spans off-hours, the effective cost is closer to the business-hours overlap than the raw elapsed time — worth adjusting the MTTR input to reflect only impacted hours.
Support and helpdesk load
A full business day down typically generates a full day of backed-up support tickets, which often clears over the following day rather than instantly at recovery.
Multi-shift operations
For 24/7 operations, treat this as one of three shifts rather than a discrete business day, and consider the full cost per day model instead.
FAQ
Cost per 8 hours, answered.
Questions that come up when framing an outage in business-day rather than calendar-day terms.
How do I calculate cost per 8 hours of downtime?
Multiply the cost per hour by 8. If the outage spans non-business hours, use only the business-hours overlap as your MTTR input for a more accurate figure.
Why use 8 hours instead of 24?
For customer-facing B2B tools and internal systems, business-hours exposure is usually the number that matters to stakeholders, since off-hours outages have limited practical impact.
Does this apply to 24/7 consumer products?
Less directly — for always-on consumer or ecommerce products, the cost per day or website downtime calculators are a better fit.
How does this relate to a maintenance window figure?
See cost per 4 hours for the half-shift version, or the full annual model.
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