Where that comes from

• Gross profit not earned£237

  £1,314 of revenue blocked, less 40% recovered later, at 30% margin

  Revenue you never take is not the same as money lost: you avoid the cost of the goods too, and some customers come back. This line is the profit that genuinely does not arrive.

• Value of enquiries never made£1,402

  438 missed visits, 3.5 lost enquiries at £400 each

  Visitors who arrive at a broken site and do not return. The recovery rate matters most here: people researching a considered purchase are more likely to try again than an impulse buyer.

• Advertising spent on a broken site£44

  £5 an hour × 2× × 4 hours

  Clicks are charged when they happen, not when the page loads. Pausing campaigns during an incident is one of the few things that reduces this in real time.

• Your team's time£810

  3 people × £45 an hour × 6 hours

  Count the hours actually consumed, not the length of the outage. Incidents pull in people who were not fixing anything, and the rest of the day rarely recovers.

• Emergency help£600

  £150 an hour × 4 hours

  Out-of-hours developer or agency rates, which are the rates you pay when you had no plan. Retained support is usually cheaper precisely because it is not an emergency.

Revenue blocked during the outage came to £1,314. Most calculators would stop there and call that your loss. We subtract the 40% who buy later and count gross profit rather than turnover, which is why the figure above is smaller and easier to defend.

What your uptime is worth per year

Trading losses only, at a normal hour. Staff time and emergency help are per incident, so leaving them out keeps this conservative.

The gap between the first two rows is what a maintained site is worth to you in a year. It is usually more than maintaining it costs.