How to calculate a marketing budget: approaches and logic

"How much to invest in marketing?" is a question with no single answer, but with clear logic. Let's break down the main approaches and why "whatever you can spare" is the worst of them.

Approach 1. A percentage of revenue

Budget = a fixed % of revenue (turnover). A simple benchmark, common in practice. The downside — it's detached from specific goals and channel effectiveness. Good as a starting point, not as dogma.

Approach 2. From goals (recommended)

Work backwards:

1. The goal — how many sales/customers you need.
2. The funnel — what the conversion to sale is, how many leads you need.
3. The cost — CPL/CAC by channel.
4. The budget = the needed number of leads × cost per lead.

This way the budget is tied to a result, not to a percentage "off the top of your head."

Approach 3. From unit economics

Start from how much you can pay per customer to stay profitable:

• You know the LTV and the acceptable CAC (LTV/CAC ≥ 3 is a common benchmark).
• While CAC is below the ceiling — scaling is profitable.
• The budget is limited not by "a sum" but by the point where acquisition stops paying off.

Approach 4. From competitors (share of voice)

A benchmark against competitors' spending so you don't "get lost" in the niche. Useful for understanding the market, but dangerous to blindly copy others' budgets.

What to build into the budget

• Tests — part of the budget for experiments (new channels, creatives).
• Top and bottom of funnel — not just performance, but reach (it makes performance cheaper).
• A reserve — for seasonality and opportunities.

Common mistakes

• "Whatever you can spare" — with no link to goals.
• Performance only, zero on reach → a rising CAC.
• No budget for tests → stagnation.
• Cutting marketing first in a crisis, losing market share.

Takeaway

Calculate the budget from goals and unit economics, not from "what's left over": the needed number of customers × the acceptable cost, with a reserve for tests and reach. We help plan budget allocation across channels to fit business goals.