There is no single right figure for an Amazon advertising budget, and any article that hands you one is guessing at your business. A sound number is worked out from three things you already know or can find: your profit margin, the most you can spend on ads per sale and still make money, and the goal you are spending towards. Get those three straight and you’re on your way to finding your realistic number.
Your advertising budget is the money you put into the ad auction to win clicks. It sits apart from the fees Amazon charges on each sale, and apart from the listing and creative that turn those clicks into orders. Most founders bundle all three into one line called marketing, and that is where overspend begins.
This post gives you the sum to run, in about ten minutes, plus the two numbers Amazon publishes that mark the floor to spend. We work with consumer brands on this every week, and the founders who set a budget from their own margin rather than a band on a chart keep far more of every sale.
Why there’s no single right Amazon advertising budget
The budget charts you find online are averages of other people’s businesses, sorted into bands like New Seller or Growing Brand. They are a starting point for a conversation, not a number to copy. A £30-a-day budget that prints money in one category loses it in another, because margin and competition decide whether a click is worth buying.
The reason is simple. Two brands can sell at the same price and spend the same on ads, and one profits while the other bleeds, purely because their costs to make and ship the product differ. A budget lifted from a brand with fatter margins than yours pushes you into spending you cannot afford, and the damage is invisible until the payout arrives light.
The number that actually governs your budget is the margin left after Amazon takes its cut. The sensible order, then, is to work out your economics first and set a budget the economics can carry, rather than the other way round. Our breakdown of what Amazon deducts from every sale is the place to pin those fees down before you go any further.
Set your budget from your own margin, and a competitor’s spend chart stops being a temptation.
Start from your margin: the break-even ACOS method
Your break-even ACOS is the share of a sale you can spend on advertising before that sale stops making money. ACOS, or advertising cost of sale, is simply your ad spend divided by the sales those ads produce, shown as a percentage. If your contribution margin is 30%, your break-even ACOS is 30%, and anything below that is profit.
Work out your contribution margin first. Your selling price, minus the cost of the goods, minus Amazon’s referral and fulfilment fees, minus VAT if you are registered, leaves the money an ad has to work within, and the percentage that becomes your break-even ACOS.
Take an illustrative example. A product sells for £20. Cost of goods, Amazon fees, and VAT come to £14, leaving £6, so the contribution margin is 30% and the break-even ACOS is 30%. Spend more than £6 in ads to win that £20 sale and you have paid to lose money. Set a target ACOS below break-even, say 20%, and every advertised sale leaves you £2 of profit after the ad cost.
From a target ACOS, the daily budget follows. Decide how many sales a day you want the ads to drive, multiply by your price and your target ACOS, and you have a daily spend ceiling. Ten sales a day at £20 with a 20% target ACOS is £40 of ad spend a day, a budget with a job attached rather than a guess.
Amazon publishes two numbers worth knowing here. The technical minimum for a Sponsored Products campaign is $1.00 a day, or the equivalent in pounds, as of September 2026. Amazon also says you can start testing from as little as $10 a day and recommends running a campaign for two to three weeks to gather enough data to read. How far a daily budget stretches depends on your cost per click, which Amazon sets by auction and which varies by category, so read your own campaigns rather than a benchmark.
The floor tells you the least you can spend to learn anything, your target ACOS tells you the most you can spend and still profit, and your budget sits between the two.
“Marketing budget” is three spends, not one
“What Should I Budget for Amazon Marketing and Advertising?” The question treats marketing and advertising as one budget. They are three: the ad spend that buys clicks, the listing and creative that turn those clicks into sales, and the management time or fees behind both. Fund the first while neglecting the second, and you pay to send shoppers to a page that does not convert.
Ad spend is the auction money. It is the only one of the three that scales directly with how hard you want to grow, which is why it gets all the attention and the other two get starved.
The listing and creative decide whether that ad spend converts once the click lands. A strong title, a full image set, and A+ content do more for your ACOS than any bid change, because they lift the conversion rate that every click is measured against. Paying to send traffic to a weak listing is one of the costlier mistakes we see new sellers make, and one of the more fixable.
The third spend is management: your hours, or a specialist’s fee. Run it yourself and the cost is time, which has a hard limit once the account grows. Bring in help, and there is a fee. Our Amazon ads management works best for brands already investing at least £1,500 a month in advertising, the point where the waste a specialist removes comfortably covers what they charge.
Decide the three budgets separately, and you stop robbing the listing to feed the ads.
Forget the “20 to 30% of revenue” rule
A common rule of thumb says to spend 20 to 30% of revenue on advertising while you grow. It is a tidy number but a poor guide because it ignores your margin. A brand on a 20% margin that spends 30% of revenue on ads loses money on purpose. Percentage-of-revenue rules describe other people’s businesses, not yours.
The pair of numbers that keep you honest are a target ACOS drawn from your own margin, applied at the campaign level, and a target TACOS, total advertising cost of sale, watched across the whole account. Read together, they tell you whether your spend is buying growth or quietly subsidising it.
Structure matters more than the size of the budget in any case. Across the accounts we manage, we see an average 42% reduction in ACOS from restructuring campaigns alone, before a penny more is spent. A smaller budget run through a clean campaign structure beats a larger one poured into a broad campaign nobody prunes.
Spend to a target you calculated, not a percentage you inherited.
How to set your budget this week
You can set a defensible budget in an afternoon. Work out your contribution margin, turn it into a break-even ACOS, pick a target ACOS below it, and choose a daily spend that clears the learning floor. Run it for two to three weeks, read the search term report, and adjust from real numbers rather than a guess.
Start with the margin. Price, minus cost of goods, minus Amazon’s fees, minus VAT, gives you the pounds an ad has to work within and the percentage that becomes your break-even ACOS.
Set a target ACOS below that break-even, so every advertised sale clears a profit. Then size the daily budget from your goal: how many sales a day you want, times your price, times your target ACOS, with the floor as your minimum. Keep it above the level that buys enough clicks to learn from across two to three weeks.
Run it, then read the search term report every week. Promote the terms that convert, add the ones that spend without selling as negative keywords, and let the budget follow what works. The budget you set on day one is a hypothesis, and the report is what turns it into a real number.
A budget you can defend beats a bigger target you cannot.
Where Reflex fits
We help UK consumer brands set an Amazon advertising budget from their own numbers, then run it so the spend earns its place. Most founders reach this question either about to launch and unsure what enough looks like, or already spending and unsure where the money goes.
If you would rather work this out with senior guidance than a chart from a blog, our one-to-one coaching is built for founders and in-house teams who want to run the channel themselves, with the sums checked by someone who does it daily. You can also follow Steve on LinkedIn for practical Amazon growth content. Either way, you will leave with a number you understand, not a pitch.