Ad budget calculator: from sales target to daily spend
This ad budget calculator works backwards. Tell it how many sales or leads you want and what each click, thousand impressions or conversion costs, and it returns the total budget, the daily, weekly and monthly spend, the clicks and impressions you will need, and the return on ad spend.
It suits small businesses planning a first campaign on Google, Meta or any other ad platform, agencies drafting a proposal, and anyone asked “how much should we spend?” The answer is only as good as the assumptions you enter, so the tool keeps each one visible and editable.
How to use the Ad Budget Planner
- Choose how you will plan: Cost per click, CPM and CTR, or Cost per conversion.
- Enter the conversions you want, the campaign length in days, and the matching costs and rates.
- Optionally add the value of one conversion to see ROAS, and a safety buffer for testing.
- Read the total and daily budget, then check the clicks, impressions and cost per conversion for sense.
Ad Budget Planner features
Three ways to plan
Start from CPC, from CPM and CTR, or straight from a target cost per conversion.
Daily, weekly and monthly
The same budget spread across days, with the 30.4-day month most platforms use.
Funnel numbers
Clicks and impressions needed, so you can sanity-check against what your audience can deliver.
ROAS and profit
Add the value of a conversion to compare the spend with what it should bring back.
The budget formulas with an example
Suppose you want 200 sales, about 2.5% of clicks convert and a click costs $0.60. Clicks needed = 200 ÷ 0.025 = 8,000. Budget = 8,000 × $0.60 = $4,800. Over 30 days that is $160 a day, and each sale costs $24. If a sale is worth $80, the return on ad spend is 200 × $80 ÷ $4,800 = 3.33×.
On a CPM basis, add the click-through rate. At a 2% CTR, 8,000 clicks need 400,000 impressions, and at an $8 CPM that costs 400,000 ÷ 1,000 × $8 = $3,200. If you already know what you can pay per conversion, the budget is simply conversions × CPA: 50 × $30 = $1,500.
| Plan from | Budget formula |
|---|---|
| CPC | conversions ÷ conversion rate × CPC |
| CPM and CTR | conversions ÷ conversion rate ÷ CTR ÷ 1,000 × CPM |
| CPA | conversions × target CPA |
Pacing and realism
- Platforms do not always spend evenly. Google Ads can spend up to twice the average daily budget on one day, capped at 30.4 times the daily budget in a month (Google Ads Help, checked 24 October 2026).
- New campaigns usually perform worse while the platform learns. Use the safety buffer to allow for it.
- Conversion rates, CPCs and CPMs change with audience, season and competition. Start with your own past data; if you have none, treat every input as a guess and revisit it after the first week.
- To check whether the resulting cost per conversion is affordable, compare it with your margin in the ROAS calculator. To solve for any single ad metric, use the CPM, CPC and CPA calculator.
Ad Budget Planner FAQ
How do I calculate an ad budget?
Divide the conversions you want by your conversion rate to get clicks, then multiply by the cost per click. 200 sales at 2.5% and $0.60 per click is a $4,800 budget.
How much should I spend on ads per day?
Divide the total budget by the number of days. The right total depends on your margins: the cost per conversion must be lower than the profit one conversion brings.
What conversion rate should I assume?
Use your own landing-page data. This tool does not supply industry averages because they vary widely; if you have none, run a small test first and use the result.
What is the difference between CPC, CPM and CPA planning?
They start from different prices: per click, per thousand impressions or per conversion. CPC and CPM plans need a conversion rate; CPM also needs a click-through rate.
Why is my platform spending more than my daily budget?
Platforms such as Google Ads may spend up to twice the daily budget on a single day while keeping the monthly total within 30.4 times the daily figure.
Is this a forecast?
No. It is arithmetic on your assumptions. Real results vary, so treat the output as a planning figure and not as financial advice.