Revenue tells you almost nothing on its own
A client paying you $12,000 a month sounds better than a client paying you $6,000 a month — until you find out the $12,000 client eats 90 hours of team time and the $6,000 client eats 20. Revenue without cost is a vanity number. The question that actually matters is margin: what's left after you account for the real cost of delivering the work.
Most agencies can tell you their total revenue instantly. Fewer can tell you, client by client, which accounts are actually profitable and which are quietly losing money every month. That gap is usually not a data problem — the time entries exist somewhere — it's that nobody has connected tracked time to a real cost figure and compared it against what the client pays.
The number underneath the number: fully loaded cost per hour
Before you can calculate margin, you need to know what an hour of a given person's time actually costs the agency — not their billed rate, their cost. This is sometimes called fully loaded cost per hour, and it's not just salary divided by hours worked.
A rough version: take annual salary, add benefits and payroll taxes, add a share of tools and overhead attributable to that person, and divide by their actual working hours in a year (roughly 2,000–2,080 for a full-time employee, less if you account for time off and non-billable internal work). The result is a cost-per-hour figure that's usually meaningfully higher than people expect — often 1.3–1.5x base salary once benefits and overhead are folded in.
This number is the missing ingredient in most agency profitability conversations. Without it, "how many hours did we spend on this client" is just a number. With it, hours convert into a real dollar cost you can compare against what the client is actually paying.
Turning tracked time into a margin figure
Once you have a cost-per-hour figure per person, client-level profitability becomes a straightforward (if occasionally uncomfortable) calculation:
- Total the hours each team member logged against a given client over a period.
- Multiply each person's hours by their cost-per-hour, then sum across the team, to get total labor cost for that client.
- Add any direct pass-through costs — subcontractors, paid tools, ad spend you're managing — that aren't already covered by labor.
- Subtract total cost from what the client paid over the same period. What's left is gross margin in dollars; divide by revenue to get margin as a percentage.
A commonly cited target is gross margin above 50–60% at the agency level, with individual clients ideally well above that — a client sitting at 20–30% margin isn't a lost cause, but it's a candidate for a scope conversation, a rate increase, or a hard look at whether the relationship is worth keeping at its current terms.
Why this usually surfaces a surprise
Almost every agency that runs this exercise for the first time finds the same pattern: a small number of clients generate most of the actual profit, a larger number are roughly breakeven, and at least one or two are quietly losing money — usually a client who negotiated a lower rate early on, or whose scope has crept without a corresponding price adjustment, or who simply requires more hand-holding than the fee accounts for.
None of this is visible from revenue alone. A $15,000/month client who requires 120 hours of a senior team's time can be less profitable than a $4,000/month client who requires 15 hours from a mid-level generalist. Margin, not revenue, is the number that should drive decisions about which relationships to grow, which to renegotiate, and which to let go.
What this requires from your systems
None of this works if time tracking and cost data live in different places that never get reconciled. The practical requirement is unglamorous: time needs to be logged against the actual client and project as work happens (not reconstructed at month-end), and someone needs to know — or the system needs to store — what each person's time actually costs the business, not just what gets billed. Once those two pieces exist in the same place, the margin calculation is arithmetic. Before that, it's guesswork dressed up as a P&L.