Plan an agency growth function
Estimate the annual revenue target and in-house cost of an agency growth function from your team size, average monthly retainer and market assumptions. Adjust the revenue, salary and ramp inputs to explore a different scenario.
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Your agency planning scenario
These estimates follow the assumptions shown below. They describe a modeled revenue target and in-house cost, rather than measured lost revenue, a forecast or a Markster price.
- Modeled annual revenue
- Modeled annual revenue to replace churn
- Modeled churn plus growth target
- Estimated new clients per year
- Modeled annual in-house cost
- Modeled payroll during ramp
In-house cost breakdown
- People
- Tools
- Owner time
| Role | Modeled FTE | Loaded annual cost |
|---|
What the estimate means
Use this as an agency planning scenario. It connects a revenue assumption, a churn-replacement target, an additional growth target and the modeled cost of an in-house growth function. Compare it with your own revenue, client history and staffing plans.
Set a revenue scenario
Team size is multiplied by revenue per employee, the selected market factor and the bounded retainer adjustment.
Estimate the annual revenue target
The lower amount applies the 20% churn-replacement assumption. The upper amount adds a further 20% growth target. Dividing by annual client value gives an approximate number of new clients, rounded to whole clients with a minimum of one.
Estimate an in-house function
Role staffing changes with team size. Loaded salaries, the tools budget and valued owner time form the annual total. The ramp subtotal shows loaded role payroll over the selected number of months.
Worked example: a 15-person agency
At the starting inputs of 15 people, a $5,000 monthly retainer and the US national market factor:
| Measure | Estimate | Calculation |
|---|---|---|
| Modeled annual revenue | $2,445,000 | 15 × $163,000 |
| Revenue to replace assumed churn | $489,000 per year | 20% × $2,445,000 |
| Additional growth target | $489,000 per year | 20% × $2,445,000 |
| Combined annual revenue target | $978,000 | Churn replacement plus additional growth |
| Approximate new clients | 8 to 16 per year | Targets divided by $60,000 annual client value, then rounded |
| Modeled annual in-house cost | $130,585 | People $83,938; tools $21,176; owner time $25,471 |
| Modeled payroll during a six-month ramp | $41,969 | Unrounded loaded annual role payroll × 6 ÷ 12 |
Amounts are rounded after calculation. Rounded subtotals can differ by a dollar from the rounded total. The default role allocation is approximately 0.71 FTE for outbound and 0.41 FTE for research and proposals; costs use the unrounded allocations.
The planning assumptions
These numerical defaults come from the retained agency calculator. Use the controls above to adjust revenue per employee, base salaries and ramp months. The market, churn, growth, tools and owner-time factors are shown here so you can interpret the estimate.
| Assumption | Value | Use |
|---|---|---|
| Revenue per employee | $163,000 per year | Starting revenue assumption, editable from $80,000 to $300,000. |
| Client retainer | $5,000 per month | Starting client value, editable from $500 to $25,000. Annual client value is monthly retainer multiplied by 12. |
| Churn replacement | 20% of modeled annual revenue | Illustrative revenue needed to replace churn, applied to the modeled revenue total. |
| Additional growth | 20% of modeled annual revenue | Illustrative growth target added to the churn-replacement amount. |
| Profit margin | 20% EBITDA | Retained profit assumption. It provides context for costs and does not alter the revenue target or hiring-cost totals. |
| Payroll load | Up to 1.4 times base salary | The multiplier rises from 1 to 1.4 as a role grows from zero to one full-time equivalent; it remains 1.4 above one. |
| Market factors | 0.85, 0.92, 1.00, 1.08 or 1.25 | The selected factor scales both revenue per employee and role salaries. These are scenario factors, not a current local salary quote. |
| Retainer adjustment | Reference $5,000; sensitivity 0.09 | Revenue per employee is multiplied by 1 + 0.09 × ln(monthly retainer ÷ $5,000), limited to 0.85 to 1.20. This is a modeling assumption. |
| Roles beyond a full-time threshold | 0.006 FTE per additional employee | For each role, staffing rises from zero at its starting team size to one FTE at its full-time threshold, then by this rate beyond that threshold. Roles at or below 0.01 FTE are excluded. |
| Tools | $10,000 per year plus $10,000 per modeled FTE | Annual tools budget used in the in-house cost estimate. |
| Owner time | 3 hours per week plus 1.3 hours per modeled FTE; capped at 14 hours | Owner time is valued at adjusted annual revenue per employee ÷ 2,080 hours × 1.4, rounded to a whole dollar per hour, across 52 weeks. |
| Ramp | 6 months | Editable from 1 to 18 months. Modeled ramp payroll is annual loaded role salaries multiplied by ramp months ÷ 12. Tools and owner time are not included in this ramp subtotal. |
Role costs and staffing assumptions
The calculator includes a role as its modeled allocation rises above 0.01 FTE. The starting and full-time team sizes below define each allocation. Base salaries are annual US dollar assumptions before market adjustment and payroll load.
| Role | Base salary (USD) | Starting team size | One-FTE team size |
|---|---|---|---|
| SDR / outbound | 62,000 | 3 | 20 |
| Researcher and proposals | 58,000 | 8 | 25 |
| Content lead | 95,000 | 30 | 45 |
| Marketing ops and CRM | 90,000 | 40 | 55 |
| Content and SEO | 78,000 | 50 | 65 |
| Head of growth | 165,000 | 60 | 75 |
| Data and reporting analyst | 92,000 | 70 | 85 |
Source attributions and dates
Source attributions retained from the July 2026 calculator. The named 2025 references provide dated context for this model. Treat the numerical values as planning assumptions and compare them with your own agency data.
- Revenue per employee
- Promethean Research, 2025.
- Attribution retained for the $163,000 starting assumption.
- Profit margin
- Agency profitability benchmarks, 2025.
- The 20% margin is an illustrative assumption attributed to 2025 agency profitability benchmarks.
- Client churn
- Focus Digital, 2025; ANA / 4As tenure.
- The calculator uses 20% as a scenario assumption. The ANA / 4As attribution is undated in the model.
- Growth
- Agency growth benchmarks, 2025.
- The 20% growth target is an illustrative assumption attributed to 2025 agency growth benchmarks.
- In-house salaries and payroll load
- BLS OEWS / ECEC; Glassdoor; SHRM.
- These salary and payroll-load attributions are undated in the model. Base salaries and payroll load are planning assumptions.
- Ramp
- Orum; Bridge Group; DePaul.
- These ramp attributions are undated in the model. Six months is an editable planning assumption.
Questions about the estimate
- How much annual revenue would this scenario target?
- At the starting $163,000 revenue-per-employee assumption, a 25-person agency at the US national market factor has modeled annual revenue of $4,075,000. The 20% churn-replacement target is $815,000; adding the 20% growth target brings it to $1,630,000. At a $5,000 monthly retainer, that is approximately 14 to 27 new clients per year. These are modeled targets, not measured lost revenue.
- What does the model include in the in-house cost?
- It adds modeled role salaries with payroll load, tools and valued owner time. At the 15-person starting inputs, the annual estimate is $130,585: $83,938 for people, $21,176 for tools and $25,471 for owner time. Role allocation changes with team size, and you can adjust base salaries. This is an in-house planning estimate, not a Markster price.
- How is the ramp estimate calculated?
- The default is six months, retained from the original model. You can choose 1 to 18 months. The result is loaded annual role payroll multiplied by the selected months divided by 12; it excludes tools and owner time. Actual hiring, onboarding and productivity depend on the role and agency.
- What churn rate does the calculator use?
- It applies 20% of modeled annual revenue to the churn-replacement scenario. The original page associated this assumption with 2025 retention references and an undated ANA / 4As tenure reference. Compare the assumption with your own client retention and revenue mix.
- Where do the assumptions come from?
- The original page named Promethean Research 2025, Focus Digital 2025, ANA / 4As, BLS OEWS / ECEC, Glassdoor, SHRM, Orum, Bridge Group and DePaul. It also used general 2025 agency profitability and growth references. The source-attribution section preserves those names and dates; the values remain illustrative planning assumptions.
Discuss the work your agency needs
Markster brings business expertise into your company and does the work to put it into practice. We build and run software, perform specialist work, develop custom software and keep adapting the work across Growth, Delivery, People and Finance.
Use your own numbers and the result you want to discuss as a starting point. The working scope, responsibilities and commercial terms are agreed for the work.