ACoS vs TACoS: what is the difference?
The short answer
ACoS divides Amazon ad spend by ad-attributed sales, while TACoS divides ad spend by total Amazon sales. ACoS shows campaign efficiency. TACoS shows how large advertising is relative to the whole sales base. Use ACoS for bids and search terms, then use the TACoS trend with total sales and margin for account-level budget decisions.
How do you calculate ACoS and TACoS?
Both formulas start with ad spend. Only the denominator changes:
- ACoS = ad spend ÷ ad-attributed sales × 100
- TACoS = ad spend ÷ total Amazon sales × 100
Amazon's own example spends $50 and earns $100 in ad revenue, producing 50% ACoS. Amazon Ads prints the formula and that 50% example in its ACoS guide.
Pull spend and attributed sales from Amazon Ads for one fixed date range. Pull total sales from Seller Central for the same marketplace, ASIN scope, and dates. Amazon defines Ordered Product Sales as the sum of item price multiplied by units ordered. Its Business Reports documentation prints that calculation.
Do not assume total sales minus attributed sales is perfectly organic. Amazon reports attributed sales on the ad-interaction date, and seller Sponsored Products use a 7-day click lookback. Amazon's attribution documentation explains both rules and why ad and retail reports differ.
What does each metric tell you?
| Question | ACoS | TACoS |
|---|---|---|
| Formula | Ad spend divided by ad-attributed sales | Ad spend divided by total Amazon sales |
| Best use | Campaign, target, placement, and search-term decisions | Account, brand, and ASIN budget decisions |
| Main context needed | Contribution margin and campaign goal | Total-sales trend, margin, stock, and product stage |
| What it cannot show alone | Whether total sales grew or paid dependence changed | Which campaign or query created the change |
ACoS is useful where Amazon attributes a sale. TACoS is useful one level up, where the business decides how much of total revenue it spends on ads. Neither is a profit metric. Product cost, Amazon fees, discounts, returns, and operating costs still sit outside both ratios.
Recent market data also argues against one universal target. In the Q4 2025 Amazon Ads US benchmark report, Sponsored Products ROAS was $5.03 and Sponsored Brands ROAS was $4.98. The Helium 10 benchmark report prints both figures. Those aggregate results are context, not a target for every category or product.
How can ACoS look fine while TACoS shows trouble?
Example with stated assumptions: assume one ASIN spends $3,000 in each month. In month one, ad-attributed sales are $10,000 and total sales are $30,000. ACoS is 30% and TACoS is 10%. In month two, ad-attributed sales remain $10,000, but total sales fall to $20,000. ACoS stays at 30%, while TACoS rises to 15%.
| Example input or result | Month one | Month two |
|---|---|---|
| Ad spend | $3,000 | $3,000 |
| Ad-attributed sales | $10,000 | $10,000 |
| Total Amazon sales | $30,000 | $20,000 |
| ACoS | 30% | 30% |
| TACoS | 10% | 15% |
The campaign ratio did not change, but ad spend became a larger share of the ASIN's smaller sales base. That is a diagnostic signal, not proof that ads caused the decline. Check price, stock, Buy Box ownership, conversion rate, organic rank, branded demand, and reporting scope before changing the account.
You can run the same calculation with your own numbers in Barlo Digital's ACoS and TACoS calculator.
What TACoS trend should you aim for?
Aim for a TACoS trend that stays within the product's contribution margin while total sales hold or grow. A falling TACoS with growing total sales can indicate that sales are expanding faster than ad spend. A flat TACoS with profitable growth can also be healthy. A rising TACoS deserves investigation, especially when total sales are flat or falling.
Do not choose a universal percentage from a blog. Amazon says there is no definitive good ACoS because the answer depends on variables such as industry, company size, and campaign frequency. Amazon's guide states that qualification directly. TACoS needs the same account-specific discipline.
Amazon launched category-specific benchmarks on November 19, 2025 and made them available at daily, weekly, or monthly intervals. The launch announcement says the benchmarks are available in Campaign Manager, Report Center, and the API. Use the closest category and campaign-goal peer set when available, but let margin set the hard ceiling.
How should you read ACoS and TACoS together?
| Movement | First interpretation | What to check next |
|---|---|---|
| ACoS down, TACoS down | Ads became more efficient and spend shrank relative to total sales | Confirm sales and contribution profit also grew |
| ACoS down, TACoS up | Ad efficiency improved, but the sales base weakened or spend grew faster | Check organic sales, branded demand, stock, and price |
| ACoS up, TACoS down | Ads became less efficient, while total sales grew faster than spend | Check whether discovery or launch activity is creating valuable demand |
| ACoS up, TACoS up | Ad efficiency weakened and spend became heavier relative to total sales | Audit queries, placements, conversion, margin, and retail readiness |
Compare consistent periods. Monthly views reduce day-to-day noise, but a weekly view can identify a sudden break. Keep the marketplace, ASIN set, currency, and sales definition fixed. Recalculate after a price change, stockout, promotion, or catalog change rather than comparing unlike periods.
What does the E021 example add?
E021 is not an Amazon benchmark, and Shopee results should not be transferred into an Amazon forecast. It shows why one return target cannot do every job. The marketplace work used different target ROAS settings for Malaysia and Singapore because one market emphasized high LTV and the other emphasized volume.
Apply the principle to Amazon at the product and campaign level. A launch, branded defense campaign, and mature profit campaign can justify different ACoS thresholds. TACoS then checks whether those individual choices fit the total account's margin and sales direction.
Sources: Amazon Ads ACoS guide; Amazon Ads attribution documentation; Amazon Seller Central Business Reports documentation; Amazon Ads benchmark launch announcement dated November 19, 2025; Helium 10 Q4 2025 Retail Media Benchmark Report, published January 2026; Barlo Digital evidence E021.
Fair questions
Is TACoS more important than ACoS?
Neither replaces the other. TACoS is better for judging ad spend against the whole Amazon sales base. ACoS is better for deciding which campaigns, targets, placements, and search terms need action. Start with TACoS and margin for the account budget, then use ACoS and conversion data to make campaign-level changes.
Can TACoS measure organic sales exactly?
No. TACoS compares ad spend with total sales, but total sales minus ad-attributed sales is not a clean organic-sales measure. Amazon Ads and Seller Central can use different dates, attribution windows, and sales definitions. Keep reporting scope consistent and treat the difference as directional unless you have reconciled the underlying order data.
How often should you calculate TACoS?
Calculate it monthly for budget and margin decisions, then monitor it weekly when spend, pricing, promotions, or inventory change quickly. Use the same marketplace, ASIN group, currency, date range, and sales definition each time. A trend built from inconsistent inputs can look precise while pointing in the wrong direction.
Need an Amazon PPC plan tied to total sales?
Barlo Digital's Amazon PPC management connects campaign decisions to product margin, inventory, ACoS, and TACoS. Review the scope and pricing, then decide whether senior-led management fits the account.