What is an advertising budget?

Setting an advertising budget is one of the more challenging marketing decisions for early-stage founders, particularly those with limited funds and no established baseline for what advertising will return. Understanding how to think about an advertising budget — rather than simply picking a number — helps founders allocate spend more deliberately and evaluate whether results justify the investment.

An advertising budget is the amount a business plans to spend on paid marketing activity over a defined period. It may be set as a fixed monthly amount, a percentage of revenue, or a target cost per acquisition multiplied by the number of customers the business aims to acquire. The right budget depends on what a customer is worth, how much it costs to acquire one, and how much the business can invest before seeing a return.

Advertising budgets for early-stage businesses are best approached as experiments — the goal of initial spend is to generate data about what works before committing to larger amounts. Starting with a small, tightly scoped campaign, measuring the results, and scaling what works is more efficient than distributing budget across multiple channels simultaneously. Our guide to advertising budgets for UK founders covers how to set, allocate, and review your spend.