How to calculate agency profitability

We ran our 15-person studio for years without a profitability number we trusted. We knew revenue, we knew the bank balance, and we assumed the gap was profit. It was not. The gap was timing, unbilled hours and a couple of projects quietly running at a loss while the busy ones carried them.

Agency profitability is not complicated to calculate. It is complicated to *see in time*. Here is the formula, a worked example, and what good looks like in 2026.

What agency profitability actually measures

Profitability is what is left after the cost of delivering the work is taken out of the revenue it earned. For an agency, the cost of delivery is mostly people's time, so the number lives or dies on whether you track hours against the right project at an honest cost rate.

Two levels matter. Project margin is the profit on a single engagement. Agency profitability is every project's margin rolled up, minus the overhead that no single project carries. Owners who only watch the agency-level number miss the project-level leaks that create it.

The formula

Project margin is straightforward:

• Delivery cost = hours logged × fully-loaded cost rate, plus pass-through costs
• Project profit = revenue − delivery cost
• Project margin = project profit ÷ revenue

The fully-loaded cost rate is the part most agencies get wrong. It is not salary ÷ hours. It is total cost of employment (salary, employer tax, benefits, software, allocated rent and admin) divided by realistically billable hours. A designer on £45,000 salary can carry a fully-loaded cost closer to £40-45 an hour once overhead is included.

A worked example

Take a £20,000 fixed-fee website project, estimated at 100 hours. At a blended cost rate of £60 an hour, planned delivery cost is £6,000, for a planned gross margin of 70%. Healthy.

Now run it the way projects actually go. Three unbilled revision rounds and a "quick" extra page push it to 150 hours. Delivery cost is now £9,000, profit is £11,000, and the margin has dropped to 55%. Add the account director's 12 unlogged hours of client comms at £90 cost and the real margin is closer to 50% - still fine, but a fifth of the planned profit gone, none of it visible until reconciliation.

What good looks like (2026 benchmarks)

Across the benchmarks, healthy agencies land at a 50-60% gross margin on client work and a 15-25% net margin after overhead. Specialist and niche agencies sit at the top of that range because positioning lets them charge more for the same delivery cost.

The biggest drag on those numbers is rarely pricing. It is leakage. PMI's 2024 research found 52% of projects experience scope creep, with an average 27% cost overrun on the work affected, and a further slice of hours is simply never invoiced. The margin was there in the proposal; it drained out during delivery.

Why month-end is too late

If profitability only appears when the accountant closes the month, you are steering by the rear-view mirror. The over-servicing has already happened. The unprofitable project is already delivered. The only decisions left are about the next project, not the one that lost money.

The agencies that protect margin move the number to where they can still act on it: phase-level, in real time. A team that can see on a Wednesday that a discovery phase has burned 70% of its budget for 50% of the deliverable will raise it. A team that finds out at month-end will not, because there is nothing left to do.

How to see margin in real time

Real-time profitability needs three things on one record: time logged against the project, a cost rate per person, and the project's budget. When those share a data model, margin recalculates the moment a timesheet is saved: no export, no reconciliation, no spreadsheet that disagrees with the tool.

That is the reason project profitability software exists, and the reason we built AgencyFlo: a designer logging two hours updates the task budget, the project margin and the client's running spend in one step. The formula above is simple. Keeping its inputs live and connected is the whole game.