How much should you spend on Google Ads for ecommerce?
There's no single right number; your budget is worked backwards from your goal. Divide the revenue you expect from Google Ads by your target ROAS and you have your budget. In a new account, start with enough to reach the volume smart bidding needs: Target ROAS in Search and Shopping requires at least 15 conversions in the past 30 days.
This post explains how we calculate a Google Ads budget for ecommerce. If you're curious about Meta, see our post on how much to spend on Meta ads. The logic is similar on Google, but the channel works differently and its bid strategies have their own data requirements.
How does a Google Ads budget work?
In Google Ads you set the budget at campaign level as an average daily budget. According to Google's help page, most campaigns can spend up to twice the average daily budget on a given day, but you won't be charged more than 30.4 times the average daily budget in a month. So a daily budget of 1,000 TL means a maximum monthly spend of 30,400 TL.
That flexibility is there so you don't miss out on high-traffic days. In practice it means a day that runs over budget isn't a mistake; judge it on the monthly total.
How do you work a budget back from your goal?
The soundest method starts from your revenue goal. The formula is simple:
Monthly ad budget = expected monthly revenue from Google Ads / target ROAS
Set your target ROAS from your margin, not from a guess. If your gross margin is thin, your break-even ROAS will be high; our break-even ROAS guide walks through the calculation.
Example: a brand that expects 300,000 TL a month from Google Ads and finds a ROAS of 5 profitable on its margin needs a monthly budget of 60,000 TL, or an average daily budget of roughly 2,000 TL.
The same calculation tells you whether your goal is realistic. If you can't fund the budget it produces, you need to lower the revenue target or your expectations of the channel.
Where should a new account start?
In an account with no data, the ROAS formula isn't enough on its own, because you don't yet know your conversion rate or cost per click. Two constraints matter here.
The first is the data smart bidding needs. Google's Target ROAS help page says Search and Shopping campaigns need at least 15 conversions in the past 30 days to use Target ROAS. If your budget can't produce that volume, the algorithm has nothing to learn from.
The second is click volume. With your average cost per click and your site's conversion rate, you can roughly work out how many clicks you need for the conversions you're aiming for.
Example: a store with an 8 TL cost per click and a 1.5% conversion rate needs about 2,000 clicks for 30 sales a month, which means a monthly budget of around 16,000 TL. These numbers are illustrative; update them with your own cost per click from Keyword Planner and your first weeks of data.
How should you split the budget across campaigns?
In ecommerce, a Google Ads budget is usually split across a few campaign types. How much goes where depends on your catalog and how well known your brand is.
| Campaign type | Role | Budget approach |
|---|---|---|
| Brand search | Capture people searching for your brand | Small share that is never switched off |
| Performance Max or Shopping | Sell through your product feed | The main body of the budget |
| Generic search | Category and product searches | Start limited to profitable keywords |
| Remarketing and Demand Gen | Bring visitors back | Added once traffic builds |
Splitting a new account's budget across too many campaigns is the mistake we see most. Each campaign learns separately, and when the budget is spread thin, none of them collects enough data. Starting with few campaigns and a clear main body, then expanding as data builds, is safer. Plan the campaign setup with the same simplicity.
What are the steps to calculate your Google Ads budget?
Follow this order to set your first budget:
- Work out your margin and break-even ROAS. Budget talk means little without knowing where profit ends.
- Decide what revenue you expect from Google Ads. Don't load your whole revenue target onto one channel.
- Use the formula to find the monthly budget. Divide expected revenue by target ROAS.
- Check the data threshold. Using your cost per click and conversion rate, confirm the budget can produce at least 15 conversions a month.
- Convert it to a daily budget. Divide the monthly budget by 30.4.
- Split it across campaigns. Put the main body into your sales campaign and keep a small, steady share for brand search.
- Treat the first four weeks as learning. Avoid frequent budget changes in that period, then update with real data.
When should you increase the budget?
If a campaign is beating its target ROAS and shows a "limited by budget" status, there's probably room to spend more. Raise the budget gradually and wait at least one conversion cycle after each increase. Google's Target ROAS page also notes that target changes can take one to two conversion cycles to show their full effect.
On the other hand, if ROAS is below break-even, more budget makes the problem bigger. Check search terms, feed quality, product pages and tracking first.
How should you plan the budget for peak seasons?
Search volume and competition rise around Black Friday and the holidays. Building the budget up gradually over a few weeks, rather than on the last day, reduces erratic behaviour under sudden load. Plan stock and your promotion calendar alongside the budget; a campaign that keeps running after the product sells out wastes money.
If you'd like to plan your Google Ads budget around your margin and goals, our performance marketing service page explains how we work. The Performetic team can review your current account in a free growth audit; pricing is shared in writing after that review.
Key takeaways
- A Google Ads budget is calculated by dividing your revenue goal by target ROAS, not guessed.
- Derive target ROAS from your margin; don't set a budget without knowing your break-even point.
- Most campaigns can spend up to twice the daily budget on a day, but monthly charges won't exceed 30.4 times the daily budget.
- Target ROAS in Search and Shopping needs at least 15 conversions in the past 30 days; your first budget should reach that.
- In new accounts, keep the budget in a few campaigns and expand as data builds.
- Increase budgets gradually, and only while ROAS is above target.