What does it mean to calculate overhead rate?
Overhead is everything the agency spends that cannot be charged to a particular client: rent, software, insurance, admin salaries, the owner's time selling, the coffee. Calculating overhead rate means taking that total and spreading it across the agency's billable hours, so that every hour sold carries its share. The formula is plain: total overhead for a period divided by total billable hours in that period. The result is the number of dollars each billable hour has to earn before it contributes anything to profit.
Some agencies express it as a percentage of direct labor cost instead of a per-hour figure. Either way the point is the same: to know what the business really costs to run, per unit of work sold.
Why it matters
Why calculating overhead rate matters
An agency that prices from salaries alone looks profitable on every job and loses money every year. The gap is overhead, and the only way to close it is to know the rate and build it into every price. Calculating it also shows which direction the business is drifting: a rising overhead rate means costs are growing faster than billable work, which is the earliest warning of a bad year most agencies ever get.
It changes hiring decisions too. A new producer who is mostly billable adds hours to the denominator; a new office manager adds cost to the numerator. Both may be right, but the rate tells you what each does to the price of the work.
In practice
How calculating overhead rate works in practice
- 01
First, gather a period of real numbers, usually the last twelve months. Separate direct costs (anything billed to a client, including the labor on client jobs) from indirect costs (everything else). Add up the indirect costs: that is the overhead. Then pull the billable hours for the same period from the time-tracking system, which is the moment many agencies discover their time tracking is not as good as they thought.
- 02
Divide overhead by billable hours. Say an agency spent four hundred thousand on overhead and sold ten thousand billable hours: every hour has to carry forty dollars of overhead before margin. That figure is added to the loaded labor cost of each role to produce the internal rate used in estimates, and the whole calculation is repeated at least once a year, or whenever costs or headcount change.
Watch out
What people get wrong about calculating overhead rate
Forgetting their own time. Owners who sell, manage and still do creative work often leave their salary out of overhead and out of direct cost, which makes the rate look lower than it is. The other mistake is dividing by total hours worked rather than billable hours, which spreads the overhead across time that nobody is paying for and understates what each sold hour must carry.
Finally, calculating it once and filing it. Rent goes up, software multiplies, people join and leave. A rate from three years ago is a story, not a number.
