All three of these get pitched as "marketing help." They are not interchangeable. A full-time CMO is a permanent operating hire. A fractional CMO is that same seniority of judgment, bought in a smaller, flexible dose. An agency retainer is outsourced execution, usually without a single accountable owner of strategy. Picking the wrong one doesn't just waste money, it wastes the months it takes to notice the mismatch.
These figures are estimates for planning purposes and are not tax, accounting or legal advice. Confirm the numbers for your own situation with your accountant or counsel.
What each one actually is
Full-time CMO. A permanent executive who owns the marketing function: budget, team, vendor relationships, channel strategy, and the calendar. They report to the CEO or board, and the job is built to last years, not a project cycle. You get full-time attention and full accountability, at full-time cost and full-time commitment.
Fractional CMO. The same seniority and the same ownership of strategy, bought in fewer hours per week, usually on a monthly retainer rather than a salary. A fractional CMO sets direction, makes the channel and positioning calls, and is accountable for results, but is not in the building 40 hours a week managing day-to-day execution. Good fractional CMOs either bring their own execution support or work alongside your existing team.
Agency retainer. A team that executes a defined scope, usually one or two channels (paid ads, SEO, content, social), for a monthly fee. Agencies are built to run campaigns, not to set company strategy. Most retainers come with an account manager, not a CMO-level decision-maker, and the agency's incentive is to keep executing the scope you bought, not to tell you that scope is wrong.
What each one costs
These numbers move with company stage, market, and scope, so treat them as the shape of the market rather than a quote.
Full-time CMO: Salary.com puts the median CMO base at $374,298 as of October 2026, with the typical range running $300,811 to $457,951. Smaller companies pay below that median, commonly $250,000 to $300,000 base. On top of base you're adding bonus, employer taxes and benefits (20 to 30 percent on top of base for a salaried executive), and a search fee, which runs 20 to 25 percent of first-year salary on contingency or around 33 percent retained. Run that math on a $250,000 to $300,000 base and the real first-year cost of a CMO hire lands somewhere between $400,000 and $600,000. Most of it recurs; only the search fee doesn't. You'll see higher numbers quoted, often by firms selling fractional services; they tend to assume a large-company salary and count equity as cash.
Fractional CMO: typically $5,000 to $15,000 a month, with $10,000 to $12,000 being a common range for an experienced operator at meaningful hours. Annualized, that's roughly $60,000 to $180,000. Set against the first-year full-time figure above, that is a saving of somewhere between half and three quarters for comparable seniority, which is worth computing from your own numbers rather than trusting a headline percentage, since most of the percentages quoted in this market come from firms selling fractional services.
Agency retainer: small businesses most commonly land in the $1,000 to $12,000 a month range depending on scope and channel count, with many full-service retainers clustering around $3,000 to $10,000 a month. The sticker price often looks cheaper than a fractional CMO, but that number buys execution hours, not a strategist who owns whether the strategy itself is right.
The question that actually decides it
Not "what can I afford," but "what decision am I missing right now." If you don't have a validated channel or a message that converts, you need someone accountable for figuring that out, that's a strategy problem, and an agency retainer won't solve it because no one on that team owns the strategy. If you have a validated channel and just need more hands executing it, an agency or a lean in-house team usually solves that for less, and a CMO-level hire, fractional or full-time, is overkill. Usually, not always: a broad multi-channel agency retainer can run past what a fractional CMO costs, so compare the specific scopes rather than assuming the agency is the cheap option. A full-time CMO only pays for itself once the company is big enough, and stable enough, to need someone in the building every day managing a function that already works.
Most early-stage companies are better served starting fractional: get the strategic ownership without the fixed cost, then decide whether to convert to full-time once the function has grown past what fractional hours can cover, or add agency execution underneath a fractional CMO's direction once there's a clear channel to scale.
Answer one question before you price any of the three: do you have a message that converts and one channel that produces predictably? If no, you have a strategy gap and an agency won't close it. If yes, you may only need execution capacity, which is the cheapest of the three options here.