Agencies calculate the true cost of delivery on retainer accounts by summing all direct labor costs (loaded hourly rates × hours logged), allocating overhead and non-billable time, then dividing by the retainer fee to find gross margin. The formula is: True Cost = (Loaded Labor + Allocated Overhead + Tool/Subcontractor Costs) ÷ Monthly Retainer. Most agencies underprice because they ignore non-billable hours and scope creep.
What "true cost of delivery" actually means
The retainer fee a client pays isn't profit. It's revenue. True cost of delivery is everything you spend to fulfill that retainer, including the hidden stuff that never makes it onto a timesheet. Most agency owners track billable hours and call it a day. That's where margins quietly bleed out.
A real cost-of-delivery model captures four buckets:
- Direct labor — fully loaded salaries of people doing the work
- Overhead allocation — rent, software, admin, PM time, leadership oversight
- Pass-through costs — subcontractors, freelancers, ad spend, stock assets
- Non-billable drag — internal meetings, revisions, account management, scope creep
Step 1: Build a loaded labor rate
The biggest mistake is using salary alone. A designer earning $80,000 doesn't cost $38/hour. Their loaded cost includes payroll taxes, benefits, equipment, and paid time off.
The loaded rate formula
Loaded Hourly Rate = (Annual Salary + Benefits + Taxes + Overhead Share) ÷ Billable Hours per Year
Most full-time staff bill far fewer hours than the 2,080 in a work year. After PTO, holidays, sick days, training, and internal admin, real billable capacity lands around 1,400–1,600 hours. So a $100,000 employee with a 1.35 burden multiplier and 1,500 billable hours costs roughly $90/hour to deploy, not $48.
| Component | Example value |
|---|---|
| Base salary | $100,000 |
| Burden (taxes, benefits ~35%) | $35,000 |
| Billable hours/year | 1,500 |
| Loaded hourly cost | $90/hr |
Step 2: Track hours against the retainer
You can't calculate true cost without time tracking, even on fixed-fee retainers. Tools like Harvest or Toggl let teams log hours per account. The point isn't to bill the client by the hour — it's to see how many hours each retainer actually consumes.
Run this monthly: total logged hours × each person's loaded rate = your direct labor cost for that account.
Step 3: Allocate overhead fairly
Overhead is everything not tied to a specific client: office, leadership salaries, sales, finance, and software subscriptions. Two common allocation methods:
- Percentage markup — add a flat 25–40% on top of direct labor
- Headcount allocation — divide total overhead by FTE count, then assign by hours
The percentage method is faster; the headcount method is more accurate for agencies with uneven team sizes. Pick one and apply it consistently across every account.
Step 4: Add pass-throughs and account management
Account management is the silent margin killer. The 90-minute weekly status call, the Slack fire drills, the QBR prep — none of it shows up unless you track it. Same goes for the senior strategist who "just reviews" deliverables for 30 minutes. Capture those hours at their loaded rate.
