Every web agency has a client that generates a lot of revenue. The one cited in sales meetings, the one that reassures when looking at the pipeline. And yet, when you do the honest math -- time spent multiplied by the loaded hourly cost, compared to the amount invoiced -- it turns out that this client may be the one dragging down margins. Not because they pay poorly, but because they consume far more time than the quote anticipated. The problem is that without reliable data, this reality remains invisible for months, sometimes years.
Why intuition isn't enough to assess client profitability
Intuition is a powerful tool for quick decisions, but it's a dangerous tool for evaluating profitability. And for well-documented reasons.
The revenue bias. A client generating 60,000 EUR per year is spontaneously perceived as a "good client." This revenue creates a halo effect that masks everything else. You don't see the 15 unbilled meetings, the 8 rounds of mockup feedback, the 3 Friday evening emergencies that mobilized a senior developer for an entire weekend.
The recency bias. You remember the last project delivered on time, not the three before it that overran by 40%. Memory is selective, favoring recent events over the overall record.
The commitment bias. The more time you've invested in a client relationship, the harder it is psychologically to acknowledge that the relationship isn't profitable. Accepting that a long-standing client is costing you money means questioning years of commercial decisions.
The lack of consolidation. Even when each project manager "senses" that a client is difficult, this information stays in people's heads. Without consolidated time tracking per client, there's no shared figure, no factual basis for decision-making.
Common mistake: Assessing client profitability based on their latest project. Client profitability is measured across the entire relationship -- all projects, all services, all unbilled extras. One profitable project doesn't necessarily offset three unprofitable ones.
The calculation method: total time x loaded hourly cost vs. revenue invoiced per client
The formula is simple. Its rigorous application is less so.
Step 1: Calculate the agency's loaded hourly cost
The loaded hourly cost incorporates everything an hour of work costs you: gross salaries, employer contributions, rent, equipment, software, overhead. The standard formula is as follows.
Loaded hourly cost = (Loaded payroll + Overhead costs) / Number of annual productive hours
For an 8-person web agency with a loaded payroll of 400,000 EUR and overhead of 80,000 EUR, based on 1,500 productive hours per team member per year (after deducting holidays, training, non-productive time):
- Total costs: 480,000 EUR
- Productive hours: 8 x 1,500 = 12,000 hours
- Loaded hourly cost: 480,000 / 12,000 = 40 EUR/h
This figure varies by location, team seniority, and overhead level. In the Paris region, expect 50 to 65 EUR/h. In other regions, 35 to 50 EUR/h.
Step 2: Consolidate time spent per client
This involves cumulating all hours spent on a given client over a period (rolling 12 months, for example). Important: you must include all time, not just billable production time.
- Development and design time, of course.
- But also project management time, meetings, phone calls, email exchanges, writing meeting notes.
- Prospecting and negotiation time on new projects for this client.
- Time spent on "quick" requests handled outside any quote ("Can you just update the text on the contact page?").
- QA, bug fixing, post-delivery support time.
It's this total that gives the true cost of the client relationship.
Step 3: Compare total cost and invoiced revenue
The comparison is arithmetic.
Concrete example: The WebStudio agency has been working with client Durand for 3 years. Over the last 12 months:
- Revenue invoiced to client Durand: 60,000 EUR excl. tax
- Total time spent: 1,300 hours (3 web projects, corrective maintenance, support, meetings, commercial proposals for 2 unsigned projects)
- Loaded hourly cost: 50 EUR/h
- Total cost of the relationship: 1,300 x 50 = 65,000 EUR
- Result: 60,000 - 65,000 = -5,000 EUR
Client Durand, who represents 20% of the agency's revenue, cost 5,000 EUR more than they brought in. And nobody knew, because nobody had ever consolidated the hours.
The calculation gives a raw result. To refine it, you can calculate the effective hourly rate per client (revenue invoiced / total hours). For client Durand: 60,000 / 1,300 = 46 EUR/h. Compared to the loaded hourly cost of 50 EUR/h, the agency loses 4 EUR for every hour worked for this client.
Toxic client profiles for profitability
Not all unprofitable clients are unprofitable for the same reasons. Identifying the profile helps understand the cause and tailor the response.
| Client profile | Typical behavior | Impact on profitability | Frequency in agencies |
|---|---|---|---|
| The scope creeper | Adds requests during the project ("while we're at it, could we also..."). Never considers it out of scope. | 30 to 60% overrun on quoted time. Rarely billed because requests come in small increments. | Very common |
| The slow validator | Takes 3 weeks to approve a mockup, then requests urgent changes. The schedule slips, the team must juggle. | Wait time that blocks resources, restart cost when the project resumes. 15 to 25% surcharge. | Common |
| The micro-reviewer | Sends 12 feedback emails instead of one consolidated document. Each email contains 1 to 3 comments. | Processing time multiplied by 3 to 5. The project manager spends more time managing feedback than moving the project forward. | Very common |
| The ghost decision-maker | The day-to-day contact approves, but "the director" overrides 2 weeks later. Systematic double validation. | Rework, team frustration, schedule extension. 20 to 40% surcharge. | Common |
| The urgency requester | Every request is "needed yesterday." The agency shifts resources, interrupts other projects, works in firefighting mode. | Interruption cost on other projects (context switching time), unbilled overtime. | Moderate |
Common mistake: Labeling a client as "difficult" without quantifying the impact. A client who requests lots of revisions but pays correctly and on time may be more profitable than an "easy" client who negotiates every quote down. Only the calculation can settle it.
The hidden cost of unprofitable clients
Beyond the direct calculation, an unprofitable client has secondary effects that are rarely quantified.
Team wear. Developers and designers working on never-ending projects lose motivation. Agency turnover is a major cost -- recruiting and training a senior developer costs between 15,000 and 25,000 EUR. A toxic client who causes an employee to leave costs far more than the direct deficit they generate.
Opportunity cost. Every hour spent on an unprofitable client is an hour not devoted to a profitable client, or to prospecting for new ones. If your team is 100% utilized but 20% of those hours go to loss-making clients, your growth capacity is reduced by that same amount.
Quality degradation. When the team works under pressure on a project that's already exceeded its budget, they cut corners. Fewer tests, fewer code reviews, less optimization. The result is a lower-quality deliverable that generates more post-delivery support -- a vicious cycle.
What to do once you've identified an unprofitable client
The diagnosis is in. The temptation is to cut ties: "We stop working with this client." In some cases, that's the right decision. In others, the situation can be corrected.
Option 1: Reframe the commercial relationship
Before breaking up, try reframing. Many clients aren't aware of the time they generate. A factual exchange, figures in hand, can change the dynamic.
Present the data without accusation: "Over your last three projects, actual time exceeded the quote by 35% on average, mainly due to validation back-and-forth. For the relationship to remain viable for both parties, I'd like to suggest we adjust how we work together."
Possible adjustments are numerous. Increase rates for upcoming projects. Bill for revisions beyond the number included in the quote. Impose a structured validation process with contractual deadlines. Bill support and "small requests" through a monthly maintenance contract.
Option 2: Limit exposure
If the client is unprofitable but strategic (visibility, sector reference, growth potential), you can limit exposure without breaking the relationship. Cap the time allocated to this client. Assign them supervised junior profiles rather than your seniors. Politely decline projects that present a high overrun risk.
Option 3: End the relationship
When reframing has failed and the client remains structurally unprofitable, the healthiest decision is to stop. It's never easy, especially when the client represents a significant share of revenue. But continuing to lose money isn't a strategy.
In practice, ending the relationship rarely happens abruptly. You finish ongoing projects, don't accept new ones, let the maintenance contract expire. The freed-up time is reallocated to profitable clients or prospecting.
Option 4: Prevent rather than cure
The best strategy is to detect unprofitability signals from the first project, not after three years of relationship. To do this, you need to track time spent vs. quoted time on each project, and aggregate this data by client.
A dashboard showing, for each client, the effective hourly rate compared to the loaded hourly cost is a powerful management tool. It transforms a vague impression ("this client is complicated") into actionable data ("this client costs us 8 EUR/h more than they generate").
Key takeaway: Client profitability isn't managed by intuition. It's measured, project by project, with reliable data. Agencies that implement this tracking systematically discover that at least 15 to 20% of their clients are loss-making -- and that this information radically changes their commercial and operational decisions.
The question "is this client profitable?" should be as natural as "is this project on track?" It's not a cynical question. It's a question of economic survival. An agency that can't distinguish its profitable clients from its loss-making ones makes commercial decisions blindly.
The calculation is simple: total time spent, multiplied by the loaded hourly cost, compared to invoiced revenue. The difficulty isn't in the formula -- it's in time collection. Without structured tracking, without consolidated data per client, it's strictly impossible to perform this calculation.
Agencies that have implemented this analysis never go back. They know exactly where to spend their time, which clients to protect, which to reframe, and which to let go. It's a discreet but decisive competitive advantage. To go further on managing your agency, consult the essential indicators for a management dashboard, or explore the solutions designed for web agencies.