What the calculator does
The ad budget calculator takes one figure, the total amount you're prepared to spend, and turns it into a working plan across channels: search, paid social, display, and so on. It does this by applying rough benchmark costs for each channel to your total, so you get an estimate of what that money might buy in each place. It's a starting point for planning, and the numbers it returns are only as good as the benchmarks behind them.
Most business owners come to advertising with a budget already in mind and no clear sense of how far it stretches. That's the gap this tool is built to close: it gives you a plausible shape for the conversation, whether that's with an agency, a colleague, or yourself.
What you need before you start
The calculator asks for a handful of inputs, and the quality of what it gives back depends on how carefully you answer them.
- Total budget: your spend for the period you're planning, monthly or for the length of a campaign.
- Objective: broadly, whether you want people to see your brand (awareness) or to act on it (clicks, sign-ups, sales), because this changes which channels the calculator weights more heavily.
- Audience: a rough sense of who you're reaching and where, since costs vary by location and by how competitive that audience is to reach.
You don't need exact figures for any of these. A sensible range is enough, because the calculator is working in estimates from the start.
How the numbers get split across channels
Two ways advertising is priced
Most digital advertising is sold in one of two ways. CPM (cost per thousand impressions) is what you pay for your ad to be shown a thousand times, regardless of whether anyone clicks it, and it's the usual pricing model for awareness campaigns on platforms like display networks and video. CPC (cost per click) is what you pay only when someone clicks, which suits campaigns built around getting people to a website or a shop, because you're paying for action.
The calculator uses whichever model fits each channel and divides your budget accordingly, so a budget aimed at awareness will be pushed toward CPM channels and a budget aimed at conversions toward CPC ones. Actual CPM and CPC rates move constantly, by season, by industry, and by how competitive the auction is on any given day, so the figures in the calculator are benchmarks. For a closer look at current UK ranges by channel, the UK ad spend reference tables are a better source than any single calculator output.
How the split is decided
Once the calculator knows your objective, it allocates a larger share of the budget to the channels that tend to perform that job well, and a smaller share to the rest. This mirrors how a media planner would think about it in practice: put the bulk of the money where the objective is best served, and use the remainder to test or support.
Reading what comes back
The output is usually a set of estimated results per channel: impressions, clicks, or both, depending on the pricing model that channel uses. Treat these as a way of comparing channels against each other, because the calculator has no way of knowing your creative, your offer, or how competitive your specific market is on the day you actually book the media.
Where the numbers are most useful is in spotting the trade-offs: a channel that looks expensive per click might still be worth including if it's the only one likely to reach the audience you actually want.
Where the estimates can go wrong
The calculator can return a figure that's wrong for your business, and it's worth knowing why before you act on it. Benchmark costs are averages across many advertisers, so a competitive sector, a poorly targeted audience, or a weak advert can all push your real costs well above what the tool suggests. It also can't see real-time auction prices, which move with demand from other advertisers bidding for the same audience at the same time.
None of this makes the calculator useless. It makes it a planning aid, and worth revisiting once you have real spend data to compare against its estimates.
What to do with the numbers
Once you have a rough split, the sensible next step is to check it against current market rates. The CPM and CPC benchmark comparator lets you compare typical costs across channels directly, which is a useful sanity check on anything the budget calculator has suggested.
If your total budget is modest, it's also worth reading Advertising on a small budget in the UK, which covers how to prioritise channels when there isn't enough money to run everything at once. And if you'd rather see the tool itself before working through the rest of this guide, the ad budget calculator is where the numbers above actually get produced.