Your ad budget planner for the next quarter

It's mid-September, which means somewhere in Adelaide right now a business owner is staring at a bank balance, thinking about Christmas, and picking an ad budget the way you pick a lotto number. Eight hundred a month? Fifteen hundred? Whatever's left after the BAS?

That's not a budget. That's a mood. A budget is a number you can explain to someone else — where it came from, what it's meant to produce, and what would make you change it. The good news is that building one takes about forty minutes and three tables in a spreadsheet, and once you've done it for one quarter you'll never go back to guessing.

Here's the planner we use with clients, laid out so you can copy it straight into a Google Sheet.

Why a quarter, and not a month or a year

A month is too short. Ad platforms need a few weeks of data before their numbers mean anything, and if you're changing your spend every four weeks you're reacting to noise rather than results. You'll turn off the campaign that was two weeks away from working.

A year is too long. Your costs move, your offer changes, a competitor starts bidding on your name, and by month five the plan on the page has nothing to do with the business you're actually running.

Three months is long enough to learn something and short enough to stay honest. It also happens to line up with how most Australian small businesses already think — BAS quarters, school terms, seasons. Build the planner in the last fortnight of the quarter before, so you start the new one already knowing what you're doing.

Tab one: the three numbers everything hangs off

Before you allocate a single dollar, you need three figures. Not perfect ones — honest ones.

• What a customer is worth to you. Not the sale price; the gross profit, and ideally the gross profit across the whole relationship, not just the first job.
• What you can afford to pay to win one. A common starting point is somewhere between 10% and 30% of that gross profit, depending on how hungry you are for growth and how much cash you can tie up while you wait for it to come back.
• How many extra customers you want this quarter. An actual number, written down, that someone could hold you to.

Multiply the second by the third and you have your quarterly ad budget. That's the whole trick. We walked through the maths in more detail in how much an Adelaide small business should spend on ads — if those three numbers feel shaky, start there and come back.

Input	Your number	Where it comes from
Average gross profit per customer		Your accounts, not your gut
Max you'll pay to acquire one		10–30% of the line above
Extra customers wanted this quarter		Your growth goal
Quarterly ad budget		Row 2 × row 3
Current cost per lead		Last quarter's ad account
Lead-to-customer rate		How many enquiries you actually close

That last pair is the reality check. If you want 30 customers, you close one in four enquiries, and leads cost you $40, you need 120 leads and $4,800 — and if your budget only stretches to $3,000, you now know the gap before you've spent anything, rather than in week eleven.

A budget you can't explain is a budget you'll abandon the first slow month. The point of writing the numbers down isn't precision — it's so that when things wobble, you're adjusting a plan instead of panicking.

Tab two: splitting it across the three months

Don't divide by three. Almost nobody's demand is flat, and October to December especially isn't — the run-up to Christmas is a different market to the first week of October, and January is a different planet again.

Split the quarter into a build month, a push month and a hold month, and weight the spend accordingly. For most retail and gift-led businesses that's a modest October while you test creative, a heavy November through the Christmas Pageant and the start of gift shopping, and a December that front-loads hard then tapers once delivery cut-offs pass. For a trade or service business it often runs the other way — quieter in December when nobody wants a bathroom pulled apart before Christmas, heavier in late January.

Month	Role	Share of budget	What you're doing
Month 1	Build	~25%	Test creative and audiences, get the tracking right
Month 2	Push	~45%	Scale whatever won in month one
Month 3	Hold	~30%	Ride the winners, stop the losers, protect margin

Then split each month's number across channels. Keep it simple: one primary channel doing the heavy lifting, one secondary channel being tested, and a retargeting line that's usually small but punches well above its weight. If you're still deciding which channel leads, the Facebook versus Google Ads comparison is the short version — demand capture versus demand creation, and which one your business actually needs first.

One rule worth keeping: set aside roughly 20% of the quarter as a test budget, ring-fenced. It's the line item everyone raids first when things get tight, and it's the one that finds you next year's winning ad. Guard it.

Tab three: the monthly check-in

The planner is worth nothing if you build it in September and open it again in January. Put a thirty-minute check-in in the calendar for the first Monday of each month and fill in one row.

Column	What you record
Spent	Actual dollars out the door
Leads	Enquiries, bookings or sales — one definition, kept consistent
Cost per lead	Spend ÷ leads
Closed	How many became customers
Cost per customer	Spend ÷ closed, against your target from tab one
Decision	Hold, increase, cut, or fix the offer

That last column is the important one, and it's the one people leave blank. Every month should end in a written decision, even if the decision is "change nothing". And keep the metric list short — the platforms will happily show you forty numbers, of which about five actually matter.

When a month goes sideways

It will. Something always does. The planner's job is to tell you which kind of sideways you're looking at:

1. Cost per lead is up, lead volume is fine. Usually competition or creative fatigue. Refresh the ads before you touch the budget.
2. Lead volume is down, cost per lead is flat. You're not reaching enough people. That's a budget or audience problem, not an ad problem.
3. Leads are fine, nothing closes. The ads are doing their job and the offer, the landing page or the follow-up isn't. Spending more here just buys more disappointment faster.
4. Everything's fine and you're nervous anyway. Leave it alone. Constant fiddling is the most expensive habit in small-business advertising.

Notice that in three of those four cases, the fix isn't money. That's the quiet value of planning a quarter properly — it stops you reaching for the budget slider every time you feel uneasy.

Do this in the last fortnight of the quarter

Build the planner before the quarter starts, not in week three of it. Forty minutes, three tables, and a calendar reminder. The first version will be rougher than you'd like, because the numbers you're working from are estimates. Do it again in three months with real figures in the columns and it gets sharper — and by the third quarter you'll have a genuine model of what a customer costs you, which is worth considerably more than any single ad campaign.

And if the honest answer to "what can I afford to pay for a customer" turns out to be less than what a customer currently costs you, that's not a failed planning session. That's the most useful thing you'll learn all quarter, found for the price of forty minutes instead of a quarter's worth of spend. It just means the next thing to fix isn't the ads — it's the offer and the maths underneath them.