ACoS is the metric that decides whether your Amazon ads make money or quietly lose it. The short answer to what is a good ACoS is: any ACoS below your break-even ACoS, which is your profit margin. This guide explains the formula, how to find your break-even point, the difference between ACoS and TACoS, and seven concrete ways to bring ACoS down without cutting into your sales.
What Is ACoS?
ACoS stands for Advertising Cost of Sales. It is the percentage of your ad-generated revenue that you spent on the ads themselves, and it is the core efficiency metric in Amazon PPC.
The formula is: ACoS = (Ad Spend / Ad Revenue) x 100. So 100 USD of spend generating 400 USD in sales is a 25% ACoS.
A lower ACoS means each advertising dollar is working harder. But the lowest ACoS is not automatically the best outcome, what matters is ACoS relative to your margin.
What Is a Good ACoS?
A good ACoS is one that sits below your break-even ACoS, so the ad-driven sale is still profitable. Because margins differ by product and category, there is no universal number. A 30% ACoS is excellent for a product with a 50% margin and a disaster for one with a 20% margin.
As a rough guide: newly launched products often run 50% to 100% ACoS on purpose, growth-stage products settle around 30% to 50%, and mature, well-managed listings frequently operate at 15% to 25%. The right target is always tied to your margin, not a benchmark.
Break-Even ACoS: The Number That Matters
Break-even ACoS equals your net profit margin after every cost: Amazon referral and FBA fees, product cost, shipping, and returns. At your break-even ACoS, an ad-driven sale makes zero profit and zero loss. Below it you profit; above it you subsidise the sale.
For example, if you sell at 30 USD with 19.50 USD of all-in costs, your profit before ads is 10.50 USD, a 35% margin, so your break-even ACoS is 35%.
Skip the manual math. Our free ACoS and TACoS calculator gives you your break-even and target ACoS in seconds.
ACoS vs TACoS
ACoS only sees ad-attributed revenue. TACoS (Total Advertising Cost of Sales) measures ad spend against your total revenue, organic and paid combined, which reveals whether your ads are building a self-sustaining business or just renting sales.
- ACoS = Ad Spend / Ad Revenue. Judges individual keywords and campaigns. Your day-to-day optimization metric.
- TACoS = Ad Spend / Total Revenue. A falling TACoS as you scale means ads are building organic rank. The health metric.
Target ACoS by Stage
| Stage | Target ACoS | Note |
|---|---|---|
| Launch (weeks 1-4) | 50-100% | Acceptable. You are buying rank velocity and reviews. |
| Growth (months 1-3) | 30-50% | Tightening as data accumulates and you cut waste. |
| Profitable (3 months plus) | Below margin | Target under your net margin so every ad sale profits. |
| Scaled / mature | 15-25% | Efficient, sustainable PPC on an established listing. |
7 Ways to Lower Your ACoS
Lowering ACoS is rarely about slashing bids. It is about removing waste and improving conversion so every click is worth more. In priority order:
- Add negative keywords weekly. Block search terms with clicks but no orders. This is the single fastest ACoS reducer and the most neglected.
- Fix your listing conversion first. A better main image, price, and bullets lift conversion rate, which lowers ACoS on the exact same traffic.
- Move proven terms to exact match. Promote converting search terms into tightly controlled exact-match campaigns.
- Lower bids on high-spend, high-ACoS keywords. Reduce, do not always kill, bids on keywords spending above target.
- Optimize placements. Shift placement modifiers toward the placements that actually convert for you.
- Tighten match types. Rein in broad match that is drifting to irrelevant queries.
- Budget discipline. Concentrate budget where and when conversion is strongest.
Every one of these lives inside a disciplined weekly routine. See the full Amazon PPC management guide for the complete workflow, or read Amazon listing optimization to raise the conversion rate that quietly drives ACoS.
When a High ACoS Is Actually Fine
During a launch, a high ACoS is an investment, not a leak. Early aggressive spend builds sales velocity and reviews, which lifts organic rank, which lowers TACoS over time. Judge a launch by whether TACoS is trending down, not by whether ACoS is low on day one.
Frequently Asked Questions
What is a good ACoS on Amazon?
There is no single good ACoS number, because it depends entirely on your profit margin. A good ACoS is any ACoS below your break-even ACoS (your profit margin percentage). For an established product, a strong ACoS is typically 15% to 25%. During a launch, an ACoS at or above your margin can be perfectly acceptable because you are buying rank and sales velocity.
How do you calculate ACoS?
ACoS = (Ad Spend / Ad Revenue) x 100. If you spent 100 USD on ads and those ads generated 400 USD in sales, your ACoS is 25%.
What is break-even ACoS?
Break-even ACoS equals your net profit margin after all Amazon fees, product cost, and shipping. If your margin is 35%, your break-even ACoS is 35%. Any ACoS below that is profitable; above it, you lose money on that sale.
Is a lower ACoS always better?
No. A very low ACoS can mean you are under-investing and leaving sales and rank on the table. The goal is the ACoS that maximizes total profit and organic growth, which is why TACoS matters.
What is the difference between ACoS and TACoS?
ACoS measures ad spend against ad-attributed revenue only. TACoS measures ad spend against your total revenue, organic plus paid. A falling TACoS as you scale means your ads are building organic rank.