Marketplace Ad Budget Calculator: Monthly and Daily Budget from Target Sales and ACoS

A good ad budget starts from the sales you want from ads and the ACoS you can afford: monthly ad spend = target ad sales × target ACoS. Amazon's own guide says there is no universal formula for a good ad budget, and that it should follow your goals and past campaign spend. So treat the result below as a plan you test, not a promise. As of November 2026, this calculator applies to any marketplace that reports ad spend and ad sales.

What the defaults are, and where they come from

The formulas for ACoS and ROAS come from Amazon Ads: ACoS = ad spend ÷ ad revenue × 100, and ROAS = ad revenue ÷ ad spend. Everything else is a placeholder. The ₹5 lakh target, 20% ACoS, ₹799 order value, ₹12 cost per click and 8% conversion rate are examples. Amazon does not publish typical CPCs and neither do we. Use your own search-term report. Amazon's guide says to base the budget on research and on past campaign expenses.

Ad budget calculator

The formula, with a worked example

Take the placeholders. You want ₹5,00,000 in ad-attributed sales this month at a 20% ACoS. Planned spend is ₹5,00,000 × 20% = ₹1,00,000, or about ₹3,333 a day over 30 days. With a 10% buffer, it is ₹1,10,000.

Now test it. At an average order value of ₹799, ₹5,00,000 means about 626 orders. At an 8% conversion rate you need about 7,825 clicks, roughly 261 a day. Spreading ₹1,00,000 over 7,825 clicks gives a break-even CPC of about ₹12.78. If your real CPC is ₹12, the plan holds. If it is ₹18, the same budget buys fewer clicks and fewer orders, and you will land above 20% ACoS.

Those numbers are examples. The method is the point: budget, then clicks, then a CPC check.

Where to get the ACoS target

Your ACoS target should sit below your break-even ACoS. Amazon's guide says ACoS must stay lower than profit margin to stay profitable. Work out break-even in the ACoS calculator. If you sell under ₹1,000, remember Amazon.in has charged zero referral fee on those products since 16 March 2026, which raises your margin and your room to bid.

Count all advertising costs

Amazon's budget guide says to include every advertising cost: creative production, distribution at CPC or CPM pricing, agencies and software. A marketplace budget line that only counts click spend understates the real cost. Its ROI guide lists ad spend, staff time and wages, production costs, overhead and creative costs, and warns that missing them distorts ROI.

How to run it month to month

1. Set the budget per campaign type, not one pot. Keep a larger share on proven keywords and a small test share.
2. Review spend against budget at a fixed schedule. Amazon's guide recommends real-time spend checks, budget alerts and a consistent reporting schedule.
3. Pause underperformers and move money to winners, as the same guide advises.
4. Raise the budget before a sale, not during it. See festive season ads budget plan and Amazon Ads budget rules and bidding.

What this calculator cannot tell you

It does not forecast organic sales that ads lift, so a plan built only on ad sales may undercount total growth (TACoS covers that). It assumes one CPC and one conversion rate for the whole account, while real accounts vary by keyword. Amazon says budget minimums apply to services managed by Amazon Ads and does not list a minimum amount on its budget guide. Check Flipkart's minimum daily budget in your own Flipkart Ads panel; it is not confirmed here.

FAQ

How much should I spend on Amazon ads each month? Amazon says there is no universal formula for a good ad budget. Start from target ad sales × target ACoS, then test it against orders and clicks. Adjust after two to four weeks of real data. A fixed percentage of revenue from a blog is not a plan.

What ACoS should I put into the calculator? Use a figure below your break-even ACoS, which is your profit per unit before ads divided by price. If you do not know it, use the ACoS calculator first. A launch phase may run higher on purpose, but cap it in rupees and in days.

Is the daily budget a hard rule? Treat it as a cap that you review. Platforms may spend more or less on a single day within a month, so look at the weekly and monthly totals. Check the campaign budget behaviour for your ad type in your own ads console, since it is not confirmed here for every format.

Does the same method work for Flipkart ads? Yes, the arithmetic is identical: ad spend, ad sales, ACoS and ROAS. The CPC and conversion inputs should come from your Flipkart ads report. See Flipkart ads guide for how its campaigns are structured.

What if the clicks needed look impossible? Then the sales target is too high for your current traffic, or your conversion rate is lower than assumed. Lower the target, improve the listing, or accept a higher ACoS knowingly. Do not raise the budget alone, because more spend at a poor conversion rate lowers profit.

Should I add a buffer? A small buffer of 10 to 20% for tests and sale days is a common planning habit, but it is our suggestion, not an Amazon rule. Keep the buffer separate from the base plan so you can see what it bought.

Turn the plan into a running budget

If you want the plan built per SKU and run weekly, Blooprint's team does this through catalogue and listing optimisation and ads management on Amazon, Flipkart and quick commerce. BlooprintAI (blooprintai.in) is our ads-automation software.