Advertising / Free calculator
Break-Even ACOS Calculator
Calculate break-even ACOS, target ACOS and ROAS from your product economics before changing Amazon PPC bids.
Set up your scenario
Let’s run the numbers.
Your result updates as you enter valid inputs. See how it’s calculated.
Understand the numbers
How this calculator works
Pre-ad contribution = selling price − pre-ad variable costs. Break-even ACOS = pre-ad contribution ÷ selling price × 100. Target ACOS = break-even ACOS − desired contribution margin. Break-even ROAS = selling price ÷ positive pre-ad contribution. Actual ACOS = spend ÷ attributed sales × 100; ROAS = attributed sales ÷ spend.
See the method in practice
Worked example
A $40 item with $26 of pre-ad costs leaves $14 contribution. Break-even ACOS is 35%, break-even ROAS is 2.86, and a 10% desired contribution margin gives a 25% target ACOS. Spending $120 for $600 attributed sales gives 20% actual ACOS and 5.00 ROAS.
Assumptions and limitations
Contribution excludes fixed overhead and income tax. A target below zero is unachievable with these inputs; zero contribution permits no ad spend and has no finite break-even ROAS. A zero denominator is shown as unavailable. Actual campaign metrics may cover a different product mix from this per-unit scenario.
Reference: Amazon Ads campaign reporting. Check your exported report’s attribution definitions before comparing periods.
A little help with the inputs
Input guide
Use consistent currencies, units and periods. Select a field for its definition.
Selling price
Net price after discounts, excluding sales tax; one unit.
Pre-ad variable costs
All per-unit product costs, fees, fulfillment and expected returns costs, excluding ads and overhead.
Desired post-ad contribution margin (%)
Percent of selling price remaining after variable costs and ads, before overhead.
Ad spend (optional) (optional)
Same currency and attribution/reporting period as attributed sales.
Attributed sales (optional) (optional)
Ad-attributed revenue, not total business revenue.
Before you make your next move
Frequently asked questions
Is break-even ACOS the same as a good ACOS?
No. Break-even consumes all pre-ad contribution. Your target must leave room for overhead and your desired earnings. There is no universal good ACOS.
Which fees should I include?
Use your actual marketplace, payment, fulfillment and other variable costs. The calculator does not fetch current Amazon fee schedules.
Do I have to share my data or email address?
No. Core results and exports work without an account or email. An enquiry is optional, with a separate unchecked choice to share an aggregate summary. Raw report rows stay local.
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