Most sellers who want to improve their ACoS start by cutting bids. Sometimes that helps. More often it just lowers impression volume while the underlying problems — wrong hours, wrong keywords, low listing conversion — stay exactly where they are.
Getting a good ACoS is not one move. It is four, done in order. This guide walks through them. Before you touch bids, you need to know what your target actually is, where your current spend is going wrong, and which lever will move the number fastest for your specific account.
Step 1: Know your target before you optimize
Sellers often say "I want a better ACoS" without a number in mind. That makes it impossible to know when you have succeeded or whether a change actually helped. The first step is calculating your break-even ACoS.
Example: if your product sells for $40 and costs $26 landed (COGS + FBA fees),
your margin is $14 / $40 = 35%.
Your break-even ACoS is 35%.
Any ACoS below 35% in this example means ads are profitable. Any ACoS above it means ads are losing money on every sale. That number is your floor. Your actual target should be below it — how far below depends on your goals.
The detailed breakdown of what "good" means for different margins and growth stages is in the what is a good ACoS guide. Get your target number before moving forward. Without it, none of the steps below have a finish line.
Step 2: Find where your current ACoS is coming from
Before changing anything, pull 30 days of campaign data filtered two ways: by hour of day, and by keyword. These two cuts will tell you where your ACoS is actually being generated.
Hour of day: Most accounts have at least a few hours where clicks cost more than usual relative to how often they convert. Overnight hours (midnight to 6am) are the most common culprit. Campaigns run by default 24 hours a day, and those early hours often have competitive CPCs from professional buyers while the actual purchasing audience is asleep. The result is spend that pushes up your total ACoS without contributing meaningful sales.
By keyword: Look for keywords with meaningful spend and zero or near-zero sales over 30 days. These are the clearest source of wasted spend. A keyword that costs you $50 and returns one sale at a high CPC is a very different problem from a keyword that costs you $50 and returns zero sales. Both drag ACoS up. Both need action.
Start with the hourly analysis. The fix there (a dayparting rule) is faster to implement and more impactful for most accounts than keyword pruning alone. More on finding wasted spend by hour and keyword if you want to go deeper on the diagnostic.
Step 3: Stop running ads during hours that hurt you
Dayparting is the fastest ACoS lever for most accounts. You define the hours your campaigns should be inactive. A scheduling rule enforces that window every day without any manual action from you.
THEN: pause all campaigns
Effect: removes lowest-converting hours from the ACoS calculation
When you pause low-converting hours, two things happen. Total spend drops (fewer wasted clicks). Sales volume stays roughly flat (those hours were not converting anyway). The ACoS calculation improves because the spend that remains is concentrated in higher-converting windows.
Parkway Home, a home goods brand, ran their full catalog 24 hours by default. Their hourly data showed that midnight to 7am had a conversion rate roughly one-third of their afternoon peak. After adding a pause rule for that window, their account ACoS dropped over the following 30 days. They did not change a single bid. The full setup guide is in the dayparting guide. The first dayparting rule walkthrough is a faster entry point if you want a step-by-step setup.
Step 4: Cut keywords that spend without converting
Once you have the hourly problem under control, turn to keyword-level waste. Sort your 30-day keyword report by spend, descending. Work down the list and ask two questions about each keyword: how many sales did it generate, and was the cost per sale within your target ACoS?
Keywords that have spent several multiples of your target cost-per-sale without generating a sale should be paused or negated. Do not rely on Amazon's automatic bid adjustment to solve this — that system optimizes for click probability, not your specific margin target.
| Keyword situation | Recommended action |
|---|---|
| High spend, zero sales over 30 days | Pause or negate immediately |
| Moderate spend, ACoS 2x+ above target | Lower bid significantly or pause |
| Low spend, ACoS above target | Watch for 2 more weeks, then decide |
| Any spend, ACoS at or below target | Keep. Consider raising budget limit. |
| High spend, good ACoS, budget capping early | Raise budget. This keyword is working. |
Work through this in spend order, largest first. The top 10 keywords by spend often account for 60 to 70% of total ad cost.
One important note: keywords that look bad at the campaign level sometimes look fine when you isolate them by match type. A broad match version of a keyword can drag ACoS up while the exact match version performs well. Check match type before pausing a keyword entirely.
Step 5: Improve your listing so each click converts better
ACoS = ad spend / ad revenue. You can improve it by reducing spend (the steps above) or by increasing revenue per click. Listing conversion rate affects revenue per click directly.
A listing converting at 8% turns 100 clicks into 8 sales. A listing converting at 15% turns the same 100 clicks into 15 sales. If your CPC stays the same and your conversion rate doubles, your ACoS roughly halves. This is often a faster path to a good ACoS than endless bid adjustments.
The four listing elements with the most impact on conversion rate are the main image, the title (particularly the clarity of the value proposition in the first 80 characters), the bullet points (specific benefits over generic claims), and the price relative to direct competitors. Before optimizing bids further, confirm that your listing is doing its job at the click level.
Step 6: Concentrate what remains in your best windows
Once wasted hours are cut and non-converting keywords are removed, the remaining spend should land in your proven conversion windows. A peak-hour budget rule ensures those windows are fully funded rather than running out of budget at 2pm.
This is the final step rather than the first because budget increases on top of a wasteful delivery schedule just amplify the problem. Do the pruning first. Then use PPC automation rules to make sure your best hours get adequate budget — a budget boost rule that lifts spend during your peak window and restores the baseline when it closes.
If you are hitting budget exhaustion before your peak window opens, the budget exhausted guide covers the specific pacing setup that keeps spend available through the full day.
What to expect from this sequence
The dayparting and keyword changes typically produce visible ACoS movement within two to four weeks as the campaigns accumulate clean data. The listing changes take longer because conversion rate improvements are slower to register in campaign-level reporting. Performance-based automation rules need 30 or more days of clean data before they are reliable enough to trust with pause authority.
Run each change for at least two weeks before evaluating it. ACoS has natural day-to-day variance. A single good or bad day does not tell you whether a change worked. The 14-day window smooths enough of that noise to give you a real read.
And watch TACoS alongside ACoS as you make these changes. If TACoS holds steady or improves while ACoS drops, the changes are working. If TACoS rises while ACoS drops, you may have cut spend that was supporting organic rank — a sign to slow down the pruning.
Frequently asked questions
How do I get a good ACoS on Amazon? Start by calculating your break-even ACoS from your product's margin, then set a target below that. From there, the four levers are: stop running ads during low-converting hours (dayparting), eliminate keywords that spend without converting, improve your listing conversion rate so each click is worth more, and use budget rules to concentrate spend in windows with the best historical performance. ACoS improves when you raise the value of each click and reduce spend on clicks that do not convert.
What is a good ACoS on Amazon? A good ACoS is any number below your break-even ACoS that still supports your sales volume goals. Break-even ACoS equals your gross margin percentage. If your margin is 35%, any ACoS below 35% means ads are profitable. How far below depends on your goals: a growth-phase seller might target 30%, while a profitability-focused seller on the same product might target 20%.
Why is my Amazon ACoS so high? High ACoS usually has one of four causes: you are running ads during hours that rarely convert, your keyword targeting is too broad and pulling in irrelevant clicks, your listing conversion rate is low so clicks rarely turn into sales, or your bids are higher than the traffic quality justifies. Pull hourly data first — if spend concentrates overnight or in early morning hours with poor conversion, a dayparting rule is the fastest fix.
How long does it take to improve ACoS on Amazon? Most accounts see meaningful ACoS improvement within two to four weeks of making structural changes like adding dayparting rules, cutting non-converting keywords, and fixing bid levels. The first week often shows a drop simply from stopping overnight spend. Performance rule changes take longer to stabilize because they need 30 or more days of data to separate signal from noise.
Does pausing ads at night help ACoS? For most accounts, yes. Overnight hours typically have the highest click costs relative to conversion rate. Pausing campaigns during your specific dead hours removes low-quality spend from the ACoS calculation. The improvement can be significant — often several percentage points — without touching bids or keywords at all.
Off Hours handles the dayparting and budget scheduling automatically so you can focus on the keyword and listing work. Start a free 14-day trial.