You pay your team for every hour they work. You only get paid for some of them. The gap between those two numbers has a name, and it quietly decides whether you make money.
Every hour is either billable, work a client pays for, or non-billable: admin, meetings, pitches, training, holiday. Both are real. Only one brings in revenue.
Utilisation is the share of available hours that are billable.
Say someone has 1,800 available hours in a year.
They bill 1,260 of them.
That's 70% utilisation.
Now connect it to money. If their time costs you £50 an hour, every non-billable hour is £50 you can't recover. Drop from 70% to 60% utilisation across a team of ten, and you've lost the equivalent of a full person's billable output.
But be careful: 100% is not the goal. Zero non-billable time means no pitching, no training, no thinking. The aim is a healthy target, often around 70 to 80% for delivery staff, tracked honestly.
Measure utilisation per person and per team. Watch the trend, not just the number. Falling utilisation is often the first sign of over-servicing or a thin pipeline.