Why Revenue Is a Terrible KPI on Its Own
You know how much you billed last month. That's the number most agency founders lead with. "We did £120k in March." It sounds good. It feels good. And it tells you almost nothing about whether your agency is actually healthy.
Revenue is a vanity metric. It doesn't tell you if you're profitable. It doesn't tell you if you're burning out your team. It doesn't tell you if you're pricing properly. And it certainly doesn't tell you if you're heading for a cash flow crisis in three months.
What you actually need is a set of financial KPIs that give you the full picture. The kind of numbers that go into proper management accounts. The kind that let you spot problems before they become emergencies.
Here are the eight agency KPIs finance-focused founders track monthly. If you're not looking at these, you're flying blind.
1. Gross Margin
Gross margin is the single most important number in your agency. It tells you how much money you keep after paying for the direct costs of delivering your work.
For most agencies, direct costs are salaries of delivery staff, freelancers, and the software tools your team uses daily. Everything else, rent, marketing, your own salary, accounting fees, is overhead.
The formula: (Revenue minus direct costs) divided by Revenue, expressed as a percentage.
If your agency bills £100k in a month and your delivery team costs are £45k, your gross margin is 55%. That's solid. A healthy agency typically runs between 50% and 65%. Below 45% and you're probably under-pricing or over-staffing. Above 70% and you might be under-investing in delivery capacity, which creates burnout.
Track this by client and by project. If one client consistently drags your margin down, you either need to raise their rate or fire them.
2. Net Profit Margin
Gross margin tells you about your delivery efficiency. Net profit margin tells you about your overall business model. This is what's left after every single cost: salaries, rent, software, marketing, accountancy, your own drawings, everything.
The formula: Net profit divided by Revenue, expressed as a percentage.
For a well-run agency, net profit margin should be between 15% and 25%. If you're below 10%, your overhead structure is too heavy. If you're above 30%, you might be under-paying yourself or not reinvesting enough, which is fine short-term but unsustainable.
Your net profit margin is the number that matters when you eventually sell. A buyer looks at your bottom line, not your top line.
3. Revenue Per Head
This is the classic agency efficiency metric. Total revenue divided by total headcount. It tells you how much revenue each person in your business generates.
The benchmark: A healthy UK agency typically runs between £80k and £150k revenue per head. A 10-person agency turning over £1.2m is at £120k per head. That's good.
If you're below £70k per head, you have too many people for the work you're selling. If you're above £160k, you might be under-staffed and running your team ragged, check your utilisation rate before celebrating.
Revenue per head varies by agency type. A recruitment agency can push higher because they have fewer direct delivery costs. A web design agency with heavy technical delivery will sit lower. The key is tracking your own trend month on month.
4. Utilisation Rate
Utilisation rate is the percentage of your team's paid hours that are actually billed to clients. If someone works 40 hours in a week and bills 32 of those to clients, their utilisation is 80%.
The benchmark: 75% to 85% is the sweet spot for most agencies. Below 70% and you're carrying too much bench. Above 90% and you have zero capacity for business development, internal projects, or handling unexpected client demands, which means scope creep will kill your margins.
Track this by role. A senior strategist might sit at 60% because they spend time on new business. A designer should be at 80% or higher. If your whole team is below 70%, you have a sales problem. If they're all above 90%, you have a pricing problem, you're not charging enough for the work.
5. Average Billable Rate
This is straightforward but often ignored. Total billable revenue divided by total billable hours. What are you actually charging per hour, on average, across all clients?
If you think you charge £100 per hour but your average billable rate comes out at £78, you have a problem. It means you're discounting, giving away free work, or not tracking time properly. All of those are margin killers.
Calculate this for each client. If Client A gives you an average rate of £95 and Client B gives you £60, you know exactly which one to push for a rate increase or replace.