The most common question from Australian businesses starting with Google Ads is how much money they need to spend. The honest answer is that it depends on your industry, your target location and how many customers you want to generate per month. But there is a straightforward formula that produces a realistic figure without guesswork.
The formula for calculating your Google Ads budget
Your required budget is derived from three variables you can estimate before launching any campaign:
- Average CPC in your industry: the cost per click your competitors are paying on searches relevant to your business
- Estimated conversion rate: the percentage of website visitors who take action (contact, call, purchase), achievable with a well-built landing page
- Leads or sales you need per month: how many enquiries or transactions you want to generate
The formula is: Budget = (Target leads × Average CPC) / Conversion rate
Practical example: a dental practice in Sydney wanting 25 new patient enquiries per month, with an average CPC of $10 AUD and a conversion rate of 6%, needs: (25 × $10) / 0.06 = $4,167 AUD/month in ad spend.
If the CPC is $5 AUD and the conversion rate is 8%: (25 × $5) / 0.08 = $1,563 AUD/month.
The result varies significantly by industry and city. That is why the starting point is always knowing the real CPCs in your specific market.
Average CPCs by industry in Australia in 2026
These ranges reflect what Australian businesses typically pay on searches with medium-to-high intent. CPCs for generic or informational terms are significantly lower but convert much worse.
| Industry | Average CPC (high intent) |
|---|---|
| Trades (plumbing, electrical, carpentry) | $3–$7 AUD |
| Pest control / cleaning services | $2–$5 AUD |
| Home renovation and building | $3–$8 AUD |
| Education and tutoring | $2–$6 AUD |
| Real estate agencies | $4–$10 AUD |
| Accounting and bookkeeping | $4–$8 AUD |
| Medical (general practice, specialists) | $5–$12 AUD |
| Dental practices | $6–$15 AUD |
| Legal services | $8–$20 AUD |
| Migration agents | $5–$12 AUD |
| Financial services and mortgages | $6–$15 AUD |
What the real minimum budget is
The minimum budget is not what Google suggests in the campaign setup wizard — those numbers tend to be conservative and do not account for the data requirements of Smart Bidding strategies.
The real minimum budget is the amount needed to generate enough conversions for the algorithm to learn and optimise reliably. Smart Bidding strategies (Target CPA, Target ROAS, Maximise Conversions) require a minimum of 30–50 conversions per month to function correctly. Below that threshold, the algorithm operates with insufficient data and can make erratic bidding decisions.
In practice, this means:
- Low CPC industries ($2–$4 AUD): minimum of $800–$1,200 AUD/month to generate enough clicks and conversion data
- Mid-range CPC industries ($4–$8 AUD): minimum of $1,500–$2,500 AUD/month
- High CPC industries ($8–$20 AUD): minimum of $2,500–$5,000 AUD/month
Below these thresholds, it is not that campaigns cannot work — it is that the results are too variable and the data volume too low to distinguish what is working from what is not. The algorithm cannot improve without enough signal.
Testing budget vs scaling budget
The testing budget is what you use in the first 1–2 months to learn: which keywords convert, which ads generate the most enquiries, which geographic areas perform best. In this phase, the goal is not to maximise return but to collect reliable data.
The scaling budget is what you apply once you have enough data to know the campaign is working. When scaling, increasing spend by 20–30% every two weeks allows the algorithm to adjust without losing accumulated learning. Doubling the budget overnight typically disrupts performance for 1–2 weeks while the system relearns.
The most common mistake Australian businesses make is starting with a very low budget, seeing no results in the first week (which is normal during the learning phase), and concluding that Google Ads does not work before they have enough data to evaluate anything.
Total cost: ad spend plus management
A Google Ads budget has two components: what goes directly to Google (ad spend) and what you pay whoever manages your campaigns (management). Ad spend pays for clicks. Management covers strategy, setup, ongoing optimisation and reporting.
A frequent misunderstanding is thinking the total cost is only what goes to Google. If you invest $2,000 AUD/month in clicks and pay $600/month in management, your total campaign cost is $2,600/month. That is the number relevant for calculating your real cost per acquisition and comparing it to the value of each customer.
For a full breakdown of how management fees are structured and what they should include, see how much Google Ads management costs in Australia.
How to know if your current budget is sufficient
If you already have active campaigns, there is a clear signal that the budget is insufficient: the “Budget limited” indicator in Google Ads. When this appears, it means your ads are stopping being shown due to daily budget exhaustion — which means you are missing potential customers who were actively searching for what you offer.
Another indicator: if the Search Impression Share for your key terms is below 60–70%, there is reachable demand your current budget is not capturing.
If your campaigns are showing the “Budget limited” flag, the priority is not to immediately increase spend — it is to first confirm the campaign structure and conversion tracking are correct, so that additional budget is not being fed into a system that is not optimising properly.
Want to know what budget your specific business actually needs to see real results from Google Ads in Australia? Let us help you work it out.