Work out the budget a target actually needs, or what a fixed budget will realistically return. Same three numbers, solved in whichever direction is useful.
At $4.50 a click and a 5.0% conversion rate, 60 conversions a month needs 1,200 clicks.
| Conversion rate | Budget | Cost per conv. |
|---|
A Google Ads budget is not a decision, it is an output. Three numbers produce it: what a click costs, how often a click converts, and how many conversions you need. Change any one and the budget changes with it.
The version of this calculation most businesses run is backwards. They pick a budget that feels affordable, spend it, and then find out what it bought. Running it forwards tells you before you commit whether the target is reachable at all, and that is usually the more useful answer.
Cost per conversion is cost per click divided by conversion rate, and it does not change no matter how much you spend. If that figure is above what a customer is worth to you, no budget fixes it. Spending more simply loses money faster.
If the account is running, take it from the last 90 days at campaign level rather than account level, because branded search will drag the average down and flatter everything built on it. If you have not launched, Keyword Planner gives a range for Australian search; plan against the top of it rather than the middle.
Click costs move. Competitive Australian categories such as legal, trades, finance and dental routinely sit well above $10 a click, while low-competition B2B terms can sit under $2. An average pulled from a global benchmark article is worth nothing.
This is the number people get wrong, and it is the number the answer is most sensitive to. Use the rate your landing page actually achieves on paid traffic, not the site-wide figure, which includes returning customers and direct traffic and will be far higher.
If you are planning a campaign that does not exist yet, be pessimistic. A plan built on an optimistic conversion rate produces a budget that is too small, which then underdelivers, which gets read as a channel problem rather than an arithmetic one.
Work back from a business target rather than picking a round number. If you need twelve new customers a month and close one enquiry in four, you need 48 enquiries, not fifty because fifty sounds tidy.
Google Ads campaigns take a daily budget, not a monthly one. The platform multiplies it by 30.4 to get a monthly charging limit, which is why the daily figure here is your monthly budget divided by 30.4 rather than by 30 or 31.
On any given day a campaign can spend up to twice its daily budget, and Google balances that out across the month. This alarms people the first time they see it. It is normal, and you will not be charged more than the monthly limit. What it does mean is that a single day's spend tells you nothing, and judging a campaign on it will lead you to switch off something that was working.
If several campaigns draw on one shared budget, the best performer and the worst performer compete for the same pool, and the one with the higher volume usually wins regardless of whether it is profitable. Separate budgets cost nothing and make the reporting honest.
Automated bidding needs conversion volume before it can do anything useful. The commonly cited figure is around 30 conversions in 30 days for Target CPA, and more for Target ROAS. Below that, the bidding model is making decisions from noise, and performance swings for reasons nobody can explain.
Two practical consequences. A budget that produces fewer than about fifteen conversions a month will struggle on automated bidding and often does better on manual or maximise clicks with tight targeting. And if the budget is genuinely small, concentrating it on one campaign and a handful of high-intent keywords will beat spreading it across a full-funnel structure every time.
There is no universal minimum. A business with a $60 cost per conversion and a $2,000 budget will gather enough data. A business with a $600 cost per conversion and the same budget will not.
A Sydney commercial services business wants 60 enquiries a month. Their landing page converts paid search traffic at 5 percent, and their average cost per click across generic search is $4.50.
Now the useful part. If the real conversion rate turns out to be 4 percent rather than 5, the same 60 enquiries need 1,500 clicks and $6,750, and the cost per enquiry rises to $112.50. A single percentage point moved the budget by 25 percent. That is why the sensitivity table sits next to the answer, and why lifting conversion rate is almost always cheaper than lifting budget.
Figures are illustrative. Returns vary by industry.
Site-wide includes direct, organic and returning visitors, all of whom convert far better than someone clicking an ad for the first time. Using it will understate the budget you need, often by half.
Branded search clicks are cheap and convert brilliantly. Including them in the average makes generic prospecting look affordable when it is not. Plan non-brand campaigns on non-brand data.
Media spend is what the platform charges. Management fees, creative, landing page work and any GST that is not claimable all sit on top. A $5,400 media budget is not a $5,400 marketing budget.
This is arithmetic, not a forecast. Auction prices move, competitors enter, seasonality shifts demand, and no plan survives contact with a live account unchanged. Use it to decide whether a target is plausible, then measure what actually happens.
Divide the number of conversions you want by your conversion rate to get the clicks you need, then multiply those clicks by your average cost per click. Sixty conversions at a 5 percent conversion rate needs 1,200 clicks, and at $4.50 a click that is a $5,400 monthly budget. Divide by 30.4 for the daily budget Google Ads actually uses.
There is no standard figure, because it depends entirely on your cost per click and conversion rate. The more useful test is whether the budget will produce enough conversions to manage the account on. Fewer than about fifteen conversions a month leaves automated bidding with too little data, and below roughly 30 conversions in 30 days Target CPA bidding tends to be unstable.
Google can spend up to twice a campaign's daily budget on any given day and balances it out across the month. You will not be charged more than the daily budget multiplied by 30.4 in a calendar month. It means daily spend is a poor signal and campaigns should be judged over weeks rather than days.
The costs shown in the Google Ads interface for Australian accounts are generally exclusive of GST, with GST added on the invoice. If you are registered for GST you can usually claim that back as an input tax credit, so the real cost to the business is the ex-GST figure. GST treatment depends on your circumstances, so confirm it with your accountant.
More than any other input. Budget is inversely proportional to conversion rate, so a drop from 5 percent to 4 percent increases the budget needed by 25 percent for the same result. This is why improving landing page conversion is almost always cheaper than increasing spend, and why a plan built on an optimistic conversion rate will underdeliver.
Google Ads only accepts daily budgets at campaign level, though you can set an account-level monthly spend limit as a safety net. Take your monthly figure, divide by 30.4, and set that as the daily budget. Avoid shared budgets across campaigns you want to compare, because the higher-volume campaign will absorb the pool regardless of profitability.
Then the target is not reachable at that cost per conversion, and there are only three levers: lower the cost per click through better targeting and quality score, raise the conversion rate with a better landing page and offer, or lower the target. Spending a small budget across a wide structure is the one approach that reliably fails.
No. This calculator works on media spend, which is what the platform charges you. Management fees, creative production and landing page work are separate costs that sit on top. Mixing them together makes campaign-level metrics such as cost per click and cost per conversion meaningless.
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The model is deliberately simplified. Among other things, it does not account for:
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A budget is a plan. These are the checks that decide whether the plan survives contact with a real account.
The return on ad spend an order has to produce before it makes you a cent.
Four questions and you get a recommended monthly split across Google Search, Meta, retargeting and local, weighted for your industry, your goal and how long your customers take to decide.
Working backwards from a revenue target, the minimum spend each channel needs, and when to move money rather than add it.
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