How to use this ACoS calculator
Use this ACoS calculator before changing Amazon PPC budgets. Enter ad spend, ad sales, total sales, and product margin. The tool shows ACoS, ROAS, TACoS, and profit after ads. It is built for fast campaign checks, not final accounting.
- Use ad spend from the same date range as ad sales.
- Use total sales when you want TACoS context.
- Use gross margin before ad spend for break-even checks.
What ACoS means
ACoS means advertising cost of sale. The formula is ad spend divided by ad sales. A 25% ACoS means you spent $25 on ads to generate $100 in attributed sales. Lower is not always better if the campaign is launching a product.
Profit-focused sellers usually compare ACoS against product margin. If margin is 35%, a 22% ACoS leaves room for profit. If ACoS rises above margin, ads can still drive sales but may lose money.
The ACoS formula
Use this formula when you want to calculate ACoS by hand: ACoS = (ad spend ÷ ad sales) × 100. A worked example: $40 in ad spend that produced $200 in ad sales returns 20% ACoS. The multiplier of 100 converts the ratio into a percentage so it lines up with how Amazon Ads reports the metric.
ACoS ranges most Amazon sellers use
There is no universal good ACoS. Margin, campaign goal, and product life cycle all change the target. As a starting frame, established sellers tend to benchmark in three bands:
- 0–20% ACoS is efficient. Ads pay back quickly and leave clear profit on most product margins.
- 20–40% ACoS is moderate. Profit depends on margin. Acceptable for ranking pushes and growth campaigns.
- 40%+ ACoS is inefficient unless you are launching a new product, defending a search term, or buying rank.
Find your break-even ACoS
Your break-even ACoS equals the margin available after Amazon fees and cost of goods. Take the selling price, subtract referral fees, FBA fees, and COGS, then express the remainder as a percentage of price. If that works out to 30%, an ACoS above 30% means each attributed order loses money on its own. Compare your calculated ACoS against this break-even before raising bids.
When to act on the result
Do not change bids from one small sample. Wait for enough clicks and orders to trust the trend. A good first check is 20 to 30 clicks per target. Larger accounts should use more data before cutting bids.
- Raise bids when ACoS is below target and inventory is healthy.
- Lower bids when ACoS beats margin for several days.
- Check search terms before pausing a campaign.
Frequently Asked Questions
What is a good ACoS on Amazon?
A good ACoS is lower than your product margin when profit is the goal. Growth campaigns can run higher when ranking or launch speed matters.
Is ACoS the same as TACoS?
No. ACoS uses ad sales. TACoS uses total sales. TACoS shows how ads affect the whole account.
Can this calculator replace Amazon Ads reports?
No. Use it for quick planning and checks. Use Amazon Ads reports for final campaign data.