ACoS and Repricing: How Advertising Costs Affect Your Minimum Price
Last updated: September 2026
Most Amazon sellers who run Sponsored Products have a repricing minimum price that does not include advertising costs. The floor calculation includes COGS, FBA fees, and referral fees. It does not include the ad spend that made the sale happen. Every sale driven by advertising where the price is at or near the floor is a sale below the true break-even.
The fix is a single formula extension: add the target ACoS rate as an additional deduction in the floor denominator. A 15% target ACoS on a product already carrying 8% referral fee and 15% target margin raises the floor by $4 to $7 per unit depending on price range. This is not a small adjustment.
TL;DR: ACoS (Advertising Cost of Sale) is total ad spend divided by total attributed ad revenue. If your ACoS is 20% and your selling price is $18.00, advertising costs $3.60 per unit. Adding this to the floor formula: (COGS + prep + FBA fee) divided by (1 minus referral fee minus ACoS minus target margin). TACoS (Total Advertising Cost of Sale) divides ad spend by total revenue including organic, the more accurate metric when you have significant organic sales. Net Margin Repricing in Repricer.com accepts advertising cost as a cost stack input, keeping the floor current as campaigns change.
What ACoS means and how it is calculated
ACoS is the percentage of attributed advertising revenue spent on the advertising that generated it. An ACoS of 20% means that for every $1.00 of revenue Amazon attributes to your Sponsored Products ads, you spent $0.20 on ads to generate it.
The ACoS formula:
ACoS = (total ad spend ÷ total attributed ad revenue) × 100
Example: $150 in ad spend, $750 in attributed ad revenue. ACoS = ($150 ÷ $750) × 100 = 20%
The per-unit advertising cost:
ACoS expressed as a rate applies directly to the selling price to give you the advertising cost per unit:
Ad cost per unit = selling price × ACoS rate
At a $20.00 selling price with 20% ACoS: Ad cost per unit = $20.00 × 0.20 = $4.00 per unit
This $4.00 is the advertising cost that produced the sale. It is a real cost of that sale and belongs in the floor calculation alongside COGS, FBA fees, and referral fees.
The distinction between ACoS and break-even ACoS:
Break-even ACoS is the ACoS at which advertising costs exactly consume your gross margin, the point where ads neither add nor subtract from profitability. For a product with 30% gross margin (after COGS and Amazon fees), the break-even ACoS is 30%. Running campaigns above break-even ACoS produces net losses on advertising-driven sales. Running below it produces positive contributions from ad-driven sales.
Most sellers know their ACoS from Seller Central's advertising reports. Fewer know their break-even ACoS. And fewer still have incorporated their actual ACoS into their repricing floor.
Why ignoring ACoS in your repricing floor is a margin trap
A repricing floor that excludes advertising costs is set too low for any product where advertising drives sales. The floor protects the margin your repricer thinks you have. It does not protect the margin you actually have after accounting for the ads that sold the unit.
The standard floor calculation (missing advertising):
Standard floor = (COGS + prep cost + FBA fee) ÷ (1 minus referral fee rate minus target margin rate)
Example:
COGS: $9.50
Prep cost: $0.50
FBA fee: $3.18
Referral fee: 8%
Target margin: 15%
Standard floor = ($9.50 + $0.50 + $3.18) ÷ (1 minus 0.08 minus 0.15) = $13.18 ÷ 0.77 = $17.11
A seller who sets their repricing minimum at $17.11 and runs Sponsored Products at 20% ACoS sells units at a loss when the repricer is near the floor:
At $17.11 selling price:
Ad cost at 20% ACoS: $17.11 × 0.20 = $3.42
Referral fee (8%): $1.37
FBA fee: $3.18
Prep: $0.50
COGS: $9.50
Total costs: $17.97
Net: $17.11 minus $17.97 = minus $0.86 per unit
Every ad-driven sale at or near $17.11 loses $0.86. The repricing floor that was supposed to protect margin is instead locking in a loss.
Why this is invisible on the dashboard:
Seller Central's business reports show revenue, FBA fees, and referral fees per order. They do not show advertising costs per order alongside selling costs. The advertising report is separate. Most sellers do not combine them per unit to see the true net outcome. The loss accumulates silently.
The correct minimum price formula when you run Sponsored Products
Adding the target ACoS rate to the floor formula's denominator gives the minimum price that covers all costs including advertising at the target ad efficiency level.
The ad-inclusive floor formula:
Ad-inclusive floor = (COGS + prep cost + FBA fee) ÷ (1 minus referral fee rate minus ACoS rate minus target margin rate)
Worked example with advertising:
Using the same product as Section 2 with a 20% target ACoS:
COGS: $9.50
Prep cost: $0.50
FBA fee: $3.18
Referral fee: 8%
Target ACoS: 20%
Target margin: 15%
Ad-inclusive floor = ($9.50 + $0.50 + $3.18) ÷ (1 minus 0.08 minus 0.20 minus 0.15) = $13.18 ÷ 0.57 = $23.12
The ad-inclusive floor is $23.12. The floor without advertising was $17.11. The difference is $6.01 per unit, the minimum selling price required to cover a 20% ACoS campaign alongside all other costs while maintaining a 15% net margin.
Verification at $23.12:
At $23.12 selling price:
Ad cost (20%): $4.62
Referral fee (8%): $1.85
FBA fee: $3.18
Prep: $0.50
COGS: $9.50
Total costs: $19.65
Net profit: $3.47
Net margin: $3.47 ÷ $23.12 = 15.0%
The formula works: at $23.12 with 20% ACoS, the seller retains exactly the target 15% net margin after all costs including advertising.
The ACoS input question:
The ACoS to use in the floor calculation is your target ACoS for the campaign, not your current ACoS. If your current ACoS is 30% but your target is 20%, the floor based on 30% ACoS would make sense if you plan to optimise campaigns down to 20%. Using the target ACoS gives the floor you need to achieve to be profitable at the intended ad efficiency level.
Book a Demo, configure an ad-inclusive repricing floor in Repricer.com that accounts for your Sponsored Products spend alongside FBA fees and COGS.
What TACoS is and when to use it instead of ACoS
TACoS (Total Advertising Cost of Sale) divides total ad spend by total revenue, including organic sales that were not driven by ads. It is the more accurate measure of total advertising burden across the business and the correct metric for the floor formula when you have significant organic sales.
The TACoS formula:
TACoS = (total ad spend ÷ total revenue from all sales) × 100
Example: $150 in ad spend, $1,500 in total revenue ($750 from ad-attributed sales, $750 from organic). TACoS = ($150 ÷ $1,500) × 100 = 10%
Compared to ACoS for the same numbers: ACoS = ($150 ÷ $750) × 100 = 20%
TACoS is 10%. ACoS is 20%. The difference is because half the sales are organic and did not require ad spend to generate them.
Why the distinction matters for the floor calculation:
Using ACoS in the floor formula charges the full advertising rate against every sale, including organic ones. If 50% of your sales are organic, this overstates the true advertising cost per unit by 2x.
Using TACoS charges the correct average advertising burden across all sales, ad-driven and organic together.
When to use ACoS vs TACoS in the floor:
Use ACoS when:
The vast majority of your sales are ad-driven (low organic rank, new product)
Your product has minimal organic sales without active campaigns
You want the most conservative (highest) floor to protect against campaign efficiency swings
Use TACoS when:
You have significant organic sales alongside advertising
Your product ranks well organically and ads supplement rather than drive most sales
You want the floor to reflect the true average advertising burden across all revenue
For a product where 70% of sales are organic and 30% are ad-driven, TACoS is typically around 6% while ACoS is 20%. Using ACoS in the floor formula would set the floor $4 to $6 per unit higher than the TACoS-based floor, making the repricer unnecessarily aggressive in holding a high minimum even when ad-driven sales are a minority.
How Net Margin Repricing accounts for advertising spend
Repricer.com's Net Margin Repricing calculates the floor from live cost inputs including advertising. The seller specifies a target ACoS or ad spend percentage as part of the cost stack. When campaign performance changes and the effective ACoS shifts, the floor updates to reflect the new ad efficiency.
The cost inputs available in Net Margin Repricing:
COGS (or landed cost per unit)
FBA fulfillment fee (pulled live from Amazon's API)
Referral fee
Returns provision
Target margin
Advertising cost rate (ACoS or TACoS as a percentage)
Adding advertising cost to this stack produces a floor calculation that matches the ad-inclusive formula in Section 3. The floor adjusts when costs change, including when the advertising cost input is updated after a campaign performance review.
The advertising cost update cadence:
FBA fees change on Amazon's schedule. COGS changes per sourcing lot. Advertising efficiency fluctuates with bid changes, keyword competition, and seasonality. The advertising cost input in the floor should be reviewed monthly alongside campaign performance reports, not only when Amazon announces fee changes.
The 10-point repricing configuration audit includes a check for whether the advertising cost input in the floor reflects current campaign performance. Schedule this audit monthly for actively advertised products.
The Net Margin Repricing page covers the full cost stack configuration including advertising inputs.
Step-by-step: calculating your true floor price including ad costs
For each active repricing ASIN where you run Sponsored Products, follow these steps to confirm the floor is set correctly.
Step 1: Pull your ACoS and TACoS from Seller Central
In Seller Central, go to Advertising > Campaign Manager > Reports. Run a campaign performance report for the past 30 days. For each ASIN you want to calculate:
Total ad spend on this ASIN
Total attributed sales (ad-driven revenue)
Total revenue for this ASIN from Business Reports
Calculate ACoS: ad spend ÷ attributed sales. Calculate TACoS: ad spend ÷ total revenue (including organic).
Step 2: Choose ACoS or TACoS for the floor calculation
If attributed ad sales represent more than 60% of total revenue: use ACoS. If organic sales represent more than 40% of total revenue: use TACoS.
Step 3: Apply the ad-inclusive floor formula
Floor = (COGS + prep cost + FBA fee) ÷ (1 minus referral fee rate minus ad cost rate minus target margin rate)
Pull the FBA fee for the ASIN from the Revenue Calculator in Seller Central. Pull the referral fee rate from the Amazon fee schedule in the Amazon seller fees guide.
Step 4: Compare to your current repricing minimum
In Repricer.com, check the current minimum price for this ASIN. Compare to the calculated ad-inclusive floor.
If current minimum is below the calculated floor: update immediately. Every sale near the current minimum is a net loss after advertising costs.
If current minimum is above the calculated floor: the floor is set conservatively. Confirm the excess margin (floor above calculated minimum) is intentional and not the result of a stale floor from a higher-ACoS period.
Step 5: Update and monitor
Update the minimum price in Repricer.com to the ad-inclusive floor. Set a monthly calendar reminder to re-run the ACoS/TACoS calculation and verify the floor remains accurate as campaign performance changes.
Key Takeaways
ACoS is total ad spend divided by total attributed ad revenue. It is a percentage of revenue, not of cost. At 20% ACoS and a $20.00 selling price, advertising costs $4.00 per unit.
A repricing floor without advertising costs is set too low for any product where advertising drives sales. Every ad-driven sale at or near the floor is a net loss.
The ad-inclusive floor formula adds ACoS (or TACoS) to the denominator: (COGS + prep + FBA fee) ÷ (1 minus referral fee minus ad cost rate minus target margin rate).
TACoS is more accurate for sellers with significant organic sales. It divides total ad spend by all revenue, not only ad-attributed revenue. Use ACoS when most sales are ad-driven. Use TACoS when organic sales are substantial.
The advertising cost input in the floor needs monthly review. Unlike FBA fees (annual) or COGS (per lot), ACoS fluctuates with campaign performance. A floor based on a stale ACoS is a floor based on a cost that no longer exists.
Action Plan
Pull ACoS and TACoS from Seller Central advertising reports for your top 10 actively advertised ASINs over the past 30 days.
For each ASIN, apply the ad-inclusive floor formula: (COGS + prep + FBA fee) ÷ (1 minus referral fee rate minus ad cost rate minus target margin rate).
Compare the calculated floor to the current minimum price in Repricer.com. Identify any ASIN where the current minimum is below the ad-inclusive floor.
Update minimum prices in Repricer.com for any ASIN where the calculated ad-inclusive floor is above the current minimum.
Decide whether to use ACoS or TACoS for each ASIN based on the proportion of attributed versus organic sales.
Set a monthly floor review for advertised ASINs. Pull the updated ACoS/TACoS figures and recalculate floors. The floor review schedule for advertised products should be more frequent than for non-advertised ones.
Run the 10-point repricing configuration audit to check whether any active floors are currently set without advertising costs on advertised ASINs.
Frequently Asked Questions
1. How does ACoS affect my repricing minimum price?
ACoS represents the advertising cost as a percentage of the selling price. If your ACoS is 20% and your selling price is $20.00, advertising costs $4.00 per unit. This $4.00 is a real cost of the sale and must be included in the minimum price floor. A floor set without this cost will allow your repricer to sell at prices that look profitable before advertising but produce a net loss after accounting for ad spend. The ad-inclusive floor formula adds the ACoS rate to the denominator: (COGS + prep + FBA fee) ÷ (1 minus referral fee rate minus ACoS rate minus target margin rate).
2. Should I include advertising costs in my repricing floor?
Yes, if advertising drives a significant portion of your sales on that ASIN. For products where most sales come from advertising (ACoS close to TACoS), omitting ad costs from the floor means the floor protects a theoretical margin that does not exist after ad spend. For products with strong organic sales and advertising as a supplement, use TACoS (total ad spend ÷ total revenue) in the floor rather than ACoS. TACoS reflects the true average advertising burden across all sales, not only ad-attributed ones.
3. What is the difference between ACoS and TACoS?
ACoS divides total ad spend by ad-attributed revenue only. TACoS divides total ad spend by all revenue, including organic sales. If you run $150 in ads that generate $750 in attributed revenue, and your total revenue is $1,500 (half organic), ACoS is 20% but TACoS is 10%. The difference is the proportion of organic sales. ACoS is more appropriate for the floor calculation when most sales are ad-driven. TACoS is more appropriate when organic sales are substantial, because using ACoS in that case overstates the advertising cost per unit across the whole catalogue.
4. How do I set a minimum price that covers my FBA fees and advertising costs?
Use the ad-inclusive floor formula: (COGS + prep cost + FBA fee) ÷ (1 minus referral fee rate minus ACoS rate minus target margin rate). Pull COGS from your cost records, FBA fee from the Amazon Revenue Calculator for the specific ASIN, referral fee rate from the Amazon fee schedule, and ACoS from your Seller Central advertising reports for the past 30 days. The result is the minimum selling price at which you retain the target margin after all costs including advertising. Update this calculation monthly as ACoS fluctuates with campaign performance.
Book a Demo, configure an ad-inclusive repricing floor in Repricer.com using Net Margin Repricing with your Sponsored Products cost stack included.
