In short
- Ad budget = orders ÷ conversion rate × cost per visitor. 30 orders at 2% need 1,500 visitors; at $0.66 each that is $990 a month.
- Then check it pays. At an $80 order and a 45% margin, those orders leave $1,080 before ads - $90 after them.
- The channel changes everything. The same $300 buys about 259 visitors on Google Search and 2,308 on display ads.
How to use the ad budget calculator
- Choose a starting point: "From an order goal" if you know the orders you want a month, "From my budget" if you know what you can spend.
- Pick a channel above to fill in its cost per visitor, or type your own from your ad reports. Then enter your conversion rate.
- Enter one order - its value and your margin before ads. The bars show whether the budget is below what the orders leave you. Copy the link to keep the result.
The examples use different conversion rates on purpose: 2% for Google Shopping and 2.5% for Search, because searchers know what they want; 1.4% for Facebook and Instagram, the average Shopify store; 1.2% for TikTok; and 0.8% for display ads, whose visitors are colder. They are assumptions - replace them with your store's own rate per channel when you have it.
How to calculate an ad budget
30 ÷ 2% = 1,500 visitors; 1,500 × $0.66 = $990 a month.
$300 ÷ $0.79 = 380 visitors; at 1.4% that is about 5.3 orders.
Find your conversion rate with the conversion rate calculator, and your cost per visitor with the CPC calculator.
What a budget buys on each channel
Visitors a month, at a typical cost per visitor for each channel:
| Channel | Cost per visitor | $100 a month | $300 a month | $1,000 a month |
|---|---|---|---|---|
| Adeagle display ads (Essential) | $0.13–$0.30 | 769 | 2,308 | 7,692 |
| Google Shopping ads | $0.66 | 152 | 455 | 1,515 |
| Facebook and Instagram ads | $0.70–$0.87 | 127 | 380 | 1,266 |
| Pinterest ads | $0.20–$1.50 | 118 | 353 | 1,176 |
| TikTok ads | $0.67–$2.13 | 100 | 300 | 1,000 |
| Google Search ads | $1.16–$4.14 | 86 | 259 | 862 |
| Reddit ads | $0.50–$2.50 | 67 | 200 | 667 |
Visitors use the middle of each range. How many of them buy differs as well - searchers and returning visitors buy more often than people who see an ad while they scroll. Which channels your margin can pay for, and twelve alternatives to the big two, are in Facebook and Google Ads alternatives for Shopify stores.
How much should you spend on ads?
Three ways to set the number - use them together:
- From your goal (this calculator): the orders you want, at your conversion rate and cost per visitor.
- From your break-even: the most you can spend is what those orders leave you after product, shipping and fees. Above it, every first order loses money - the CPA calculator shows the limit per order.
- From your revenue: a rule of thumb often credited to the US Small Business Administration is 7-8% of revenue for businesses under $5 million a year; Gartner found large companies spending 7.7% in 2025. It tells you what the business can afford - not what your goal costs.
When the goal costs more than the break-even, don't just cut the goal. Look at the three numbers behind it: a cheaper channel, a higher conversion rate, or a bigger order (bundles, a free-shipping threshold) each move the budget below the line.
Minimum budgets by channel
| Channel | Minimum | What it means in practice |
|---|---|---|
| Facebook and Instagram | A few dollars a day | The system learns best at about 50 results a week per ad set |
| Google Ads | None | Start Shopping ads on your few best sellers |
| Microsoft Ads | None | Copy your Google campaigns once they work |
| TikTok | $50 a day per campaign, $20 per ad group | About $1,500 a month at the campaign minimum |
| None | Judge it on 30 days - Pinterest buyers plan ahead | |
| $5 a day | Pick the communities about your product | |
| Adeagle | $29 a month (Essential) | The price is your ad budget; retargeting from $99 (Professional) |
How big should a first test budget be?
Big enough for about 1,000 visitors on one channel, over two to four weeks. At a 1.4% conversion rate that is around 14 orders - few enough to swing by chance, but enough to see whether the channel sells at all. Fewer visitors can't tell you much.
- Display ads on Adeagle's Essential plan: about $130
- Google Shopping: about $660
- Facebook and Instagram: about $790
- Google Search: about $1,160
Tag every link with the UTM builder so Shopify shows which orders the channel brought, decide your break-even before you start, and test one channel at a time. The full plan is in how to test a new channel without wasting money.
What this calculator does not tell you
- Repeat orders. It counts first orders only. Customers who come back can make a loss on the first order worth taking - see the customer lifetime value calculator.
- Your real conversion rate per channel. One rate for all visitors is an average; measure each channel separately once it runs.
- The season. Ads cost more from October to December, when big stores raise their budgets - and shoppers buy more, too.
- Sales after a view. Display ads also bring buyers who saw the ad and came back later without a click. Adeagle counts those as post-view conversions.
By Bart Ziem, Adeagle · Formulas: standard definitions · Costs per visitor: published 2025-2026 ecommerce benchmarks, shown as ranges because sources differ (listed in the alternatives guide); Adeagle: what stores paid per real visitor, Aug–Sep 2026 · Minimum budgets: the platforms' ad managers · Rules of thumb: SBA (as commonly cited), Gartner CMO Spend Survey 2025 · Shopify conversion benchmark: Littledata, via Nudgify · Examples, not promises