ACoS is the number every Amazon ads report puts in front of you, and it answers a narrow question: how much did you spend for each dollar of sales that Amazon credits to your ads? It says nothing about the organic sales your ads helped create, or the organic sales they replaced. That is what TACoS is for.
Read alone, either number pushes you into bad calls: cutting ads that were lifting organic rank, or scaling ads that mostly buy sales you would have made anyway. The prompts below calculate both correctly from your own reports, read the trend between them, and turn that into budget and bid decisions you can review.
How to use them: export the reports named in each prompt, paste them where you see square brackets, and fill in your own thresholds. Any output that changes a bid or budget is a draft for you to review, not an instruction.
ACoS, TACoS and ROAS: the formulas
Metric
Formula
Answers
Blind spot
ACoS
Ad spend / ad-attributed sales x 100
How efficient are my ads on the sales they get credit for?
Ignores organic sales and the halo of ads
ROAS
Ad-attributed sales / ad spend
The same thing, inverted (ROAS 4 = ACoS 25%)
Same as ACoS
TACoS
Ad spend / total sales x 100
What share of all revenue goes to advertising?
Says nothing about which campaign works
Break-even ACoS
Profit margin before ad spend, as a percent of price
At what ACoS does a sale stop making money?
Needs your real COGS and fees
An example with made-up numbers: in a month you spend $2,000 on ads, ads are credited with $8,000 of sales, and total sales for the same products are $25,000. ACoS is 25%, ROAS is 4.0 and TACoS is 8%.
Where the numbers come from
Ad spend and attributed sales come from Amazon Ads reports. Total sales come from Seller Central, usually the Business Reports Detail Page Sales and Traffic by Child Item report (Ordered Product Sales, Units Ordered, Sessions - Total). TACoS is not a standard column in either place, so you calculate it, and total spend must include Sponsored Products, Sponsored Brands and Sponsored Display.
Two traps. Attribution windows differ by ad type and seller type (Sponsored Products is commonly 7 days for sellers, Sponsored Brands and Display 14 days); check the current Amazon Ads help before comparing them. And some Sponsored Products downloads label ACoS as Total Advertising Cost of Sales (ACOS). Despite the word total, that column is ACoS, not TACoS.
Act as an Amazon advertising analyst. Calculate ACoS, ROAS and TACoS by ASIN for [month] from two files. File 1: Sponsored Products advertised product report with Advertised ASIN, Spend, 7 Day Total Sales, 7 Day Advertised SKU Sales and 7 Day Other SKU Sales. File 2: Business Report Detail Page Sales and Traffic by Child Item with Child ASIN and Ordered Product Sales. Add Sponsored Brands and Display spend from [paste totals by ASIN or campaign]. Join on ASIN. Output: ASIN, total ad spend, attributed sales, total sales, ACoS, ROAS, TACoS. Flag ASINs where attributed sales exceed total sales and explain the likely attribution reason. File 1: [paste]. File 2: [paste]
Tip: Ask the model to show its working for two ASINs. If the math on those is right, the rest usually is.
Act as an Amazon profitability analyst. For each ASIN below, calculate break-even ACoS: (price - COGS - referral fee - FBA fulfillment fee - [other per-unit costs]) / price x 100. Then propose a target ACoS that leaves [10] points of margin, and the TACoS I can afford at my current share of sales from ads. Output a table: ASIN, price, unit costs, margin before ads, break-even ACoS, target ACoS, affordable TACoS. Mark any cost I did not provide instead of guessing it. Data: [paste ASIN, price, COGS, referral fee, FBA fee]
Why: A good ACoS is a property of your margin, not of the category. Fee amounts change, so take them from your current fee preview or settlement data.
Read the four TACoS vs ACoS patterns
The real signal is how the two numbers move against each other over several weeks.
ACoS
TACoS
What it usually means
Consider
Flat or down
Down
Organic sales grow faster than ad spend
Keep going; test more reach on winners
Up
Flat or down
Ads less efficient, but total sales grow
Fine during a launch or rank push, if it is planned
Down
Up
Ads take a bigger share of sales; organic shrinks or is cannibalized
Check branded spend and organic rank
Up
Up
Spending more for less
Cut waste first, then revisit targets
Prompt 3 · Read the four TACoS vs ACoS patternsChatGPT Claude
Act as an Amazon ads strategist. Below are [13] weeks of ad spend, attributed sales and total sales for my account and my top [10] ASINs. Calculate weekly ACoS and TACoS, then a 4-week rolling average of each. Put every ASIN into one of four patterns: both falling, ACoS up with TACoS flat or down, ACoS down with TACoS up, both rising. For each ASIN give the pattern, the evidence and one question I should answer before changing anything. Data: [paste weekly table]
Prompt 4 · Read the four TACoS vs ACoS patternsChatGPT Claude
Act as an Amazon growth analyst. Estimate organic sales for each ASIN as total sales minus ad-attributed sales, and show weekly ad spend next to weekly organic sales for [13] weeks. Tell me whether organic sales rise when spend rises, fall when it falls, or show no clear link. State plainly that this is a rough approximation, because attribution can credit ads with sales that would have happened anyway and miss sales ads influenced. Data: [paste weekly spend, attributed sales and total sales by ASIN]
Prompt 5 · Read the four TACoS vs ACoS patternsChatGPT Claude
Act as an Amazon PPC auditor. From the search term report below (Customer Search Term, Impressions, Clicks, Spend, 7 Day Total Sales, 7 Day Total Orders (#)), separate search terms that contain my brand [brand name] or product line names [names] from the rest. Show spend, sales and ACoS for each group and the share of total spend going to branded terms. If branded ACoS is very low and branded spend is growing while TACoS rises, outline a test to measure cannibalization: which campaigns to reduce, for how long, and which metric decides the result. This is a plan for me to review, not a change to make. Data: [paste search term report]
Tip: Branded campaigns often show the best ACoS in the account and the weakest case for more budget. Only a test tells you which sales they really add.
Set TACoS targets by product stage
There is no universal good TACoS. A product in launch is meant to run a high TACoS while it earns rank; a mature product with strong reviews should need less. Set the target per stage and per product from your own margin.
Stage
Primary goal
Watch
Launch
Sessions, reviews and organic rank
TACoS falling week by week; ACoS can run above break-even by plan
Act as an Amazon brand manager. Classify each ASIN below as Launch, Growth, Mature or Wind-down, using months on sale, review count, the trend in units ordered and the trend in organic sales. For each ASIN, propose a target ACoS and a target TACoS based on its break-even ACoS and its stage, with one sentence of reasoning. Use only my break-even numbers, no outside benchmarks. Data: [paste ASIN, launch date, reviews, 13-week units, organic sales trend, break-even ACoS]
Act as an Amazon launch strategist. I am launching [ASIN] at [price] with a break-even ACoS of [x]% and a launch ad budget of [amount] over [12] weeks. Draft a week-by-week TACoS glide path: the TACoS I can accept in weeks 1 to 4, where it should be by week 8 and by week 12, and the organic sales share that would justify each step. Add a checkpoint each month with the numbers that tell me to continue, slow down or stop the push. Label every target as my plan, not a forecast. Data: [paste first weeks of sales, sessions and spend if available]
Act as an Amazon advertising budget planner. My monthly ad budget is [amount]. Using the table below with each ASIN's spend, ACoS, TACoS, break-even ACoS and stage, propose a reallocation: which ASINs lose budget, which gain, and by how much, so that account TACoS moves toward [target]% without any Mature ASIN running above break-even ACoS. Show the budget before and after per ASIN and the expected effect as a range, not a promise. Mark every change as a proposal for my review. Data: [paste table]
Find where ad spend leaks
When both numbers rise, the waste is usually in a few places: search terms that never convert, an ad type that drags the average, or a placement you overpay for. Broader diagnostics are in our guide to analyzing Amazon ad performance.
Act as an Amazon PPC analyst. From the search term report below, list search terms with at least [15] clicks and zero orders, and terms with an ACoS above [2] times my break-even ACoS of [x]%. For each, show spend and clicks, and recommend negative exact, negative phrase, bid reduction or keep, with a one-line reason. Estimate how much account TACoS would fall if the spend on the negatives stopped and nothing else changed, labeled as an upper bound. Data: [paste search term report]
Why: Cutting non-converting spend lowers ACoS and TACoS together, which makes it the safest first move. For the full negative keyword workflow, see our negative keyword prompts.
Act as an Amazon ads analyst. Below are campaign reports for Sponsored Products, Sponsored Brands and Sponsored Display for [period], each with Campaign Name, Spend and attributed sales. Total each ad type's spend, attributed sales and ACoS, and its contribution to account TACoS using total sales of [amount]. Point out where attribution windows differ so I do not compare the types unfairly. Rank the ad types by contribution to TACoS and tell me where to look first. Data: [paste the three reports]
Act as an Amazon bid strategist. Below is my Sponsored Products placement report with Campaign Name, Placement (top of search, rest of search, product pages), Impressions, Clicks, Spend and 7 Day Total Sales. For each campaign, show ACoS by placement and flag placements where ACoS is more than [1.5] times the campaign average. Suggest whether to lower the top of search or product page bid adjustment, and by how much, as a draft I will review. Data: [paste placement report]
Build a weekly TACoS review
A monthly look is too slow to catch a TACoS drift. A weekly review with the same few numbers is enough. Campaign structure for scaling once the numbers are healthy is covered in our campaign strategy prompts.
Tip: The weekly review is where the export work piles up, because TACoS needs ad spend from Amazon Ads and total sales from Seller Central side by side, every week. DataDoe connects both, plus Vendor Central, to Claude, ChatGPT and other AI clients through MCP in one joined schema, refreshed daily, so the model reads spend and total sales without a paste.
Act as the head of advertising for an Amazon brand. Using last week's and the previous four weeks' data below, write a weekly review of no more than 250 words: account ACoS, TACoS and ad spend against target, the three ASINs that moved TACoS most and why, the pattern each sits in, and up to five proposed actions with the expected effect on TACoS. Separate facts from interpretation. End with the decisions I need to make this week. Data: [paste weekly ASIN table with spend, attributed sales, total sales, targets]
Act as a skeptical Amazon finance reviewer. Check the ACoS and TACoS analysis below before I act on it. Recalculate three random rows from the source data, confirm that total spend includes every ad type, that total sales come from the same dates and marketplace as spend, and that no ACoS column was mistaken for TACoS. List every error or assumption you find, and say whether the conclusions still hold. Analysis: [paste]. Source data: [paste]
FAQ
What is TACoS on Amazon?
TACoS, total advertising cost of sales, is your ad spend divided by your total sales, organic and ad-attributed together, times 100. It shows what share of all revenue goes to advertising.
What is the difference between ACoS and TACoS?
ACoS divides ad spend by the sales Amazon attributes to ads, so it measures ad efficiency. TACoS divides the same spend by all sales, so it shows how dependent the business is on ads and whether ads help organic sales grow.
What is a good ACoS on Amazon?
It depends on your margin. Your break-even ACoS equals your profit margin before ad spend, so a good ACoS sits below that number for mature products, and can run above it during a planned launch.
Why is my TACoS going up?
Either ad spend is growing faster than total sales, or organic sales are falling. Check whether branded spend grew, whether organic rank or stock changed, and whether new campaigns are buying sales you already won organically.
Does Amazon show TACoS in Seller Central?
Not as a standard report column. Most sellers calculate it from total ad spend in Amazon Ads and total sales from Business Reports, for the same dates and marketplace.
DB
David Brooks
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