Amazon PPC Bid Calculator

Turn a target ACoS and conversion rate into the most you can pay per click, and check it against your current cost per click.

Your numbers

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Average order value from ads

Ad sales ÷ ad orders, or your selling price for single-unit orders.

Conversion rate (orders ÷ clicks)

From your search term or targeting report. New keywords: start with your listing's unit session percentage.

Target ACoS

Break-even ACoS (margin before ads)

Use the break-even ACoS calculator if you don't know it.

Current cost per click (optional)

Your result · updates as you type

Maximum bid (cost per click)

$0.90

Each click is worth $3.60 in sales ($29.99 × 12%). Paying $0.90 a click lands at your 25% target ACoS.

Break-even bid: $1.15
Sales per click: $3.60
ACoS at your current CPC: 26.4%

This is the most you can pay on average. Amazon's auction often charges less than your bid, and placement adjustments raise it, so recheck ACoS after a week.

Maximum bid at each target ACoS

15%

$0.54

20%

$0.72

25%

$0.90

30%

$1.08

35%

$1.26

40%

$1.44

Breakdown

Sales per click = order value × conversion rate: $3.60
Max bid = sales per click × target ACoS: $3.60 × 25% = $0.90
Break-even bid = sales per click × break-even ACoS: $3.60 × 32% = $1.15

From conversion rate to a maximum bid

Sales per click = average order value × conversion rate

Maximum bid = sales per click × target ACoS

Worked example (the calculator's starting values)

Average order value: $29.99
Conversion rate: 12%
Target ACoS: 25%
Break-even ACoS: 32%

Sales per click: 29.99 × 12% = $3.60. Maximum bid: 3.60 × 25% = $0.90. At the current $0.95 cost per click, ACoS runs 26.4%, just above target.

Using the bid in Campaign Manager

This is an average, not a guarantee. Amazon's auction often charges less than your bid, and placement adjustments (top of search, product pages) can raise the amount actually paid, so recheck ACoS after a week of data.
New keywords have no conversion rate yet. Start with your listing's overall unit session percentage as a stand-in, then swap in the keyword's own rate once you have clicks.
Break-even bid vs target bid. The break-even bid (using your break-even ACoS) is the ceiling where ad-driven orders stop being profitable. The target bid, using a lower target ACoS, is where most sellers actually want to sit.

When the bid isn't the problem

If your current cost per click is already near or above the break-even bid, lowering the bid only slows spend: it doesn't fix an unprofitable keyword. Check conversion rate and price first; a bid that's correct for a 12% converter can be too high for the same keyword converting at 6%.

Questions people ask

How do I calculate my max Amazon PPC bid?

Multiply your average order value by your conversion rate to get sales per click, then multiply that by your target ACoS. This calculator does the math and shows the break-even bid alongside it.

What conversion rate should I use for a new keyword?

Your listing's overall unit session percentage is a reasonable starting point until the keyword has enough clicks of its own to trust its number.

Why is my bid lower than what I'm actually paying?

Check whether Amazon's auction is charging your full bid, and whether placement adjustments for top-of-search or product page placements are raising the effective cost per click above your base bid.

What's the difference between the break-even bid and the max bid?

The break-even bid uses your break-even ACoS, the point where ad-driven orders earn zero profit. The max bid uses your target ACoS, which is usually set below break-even to keep some profit on ad sales.

Does a higher bid always win more sales?

Not necessarily profitably. A higher bid can win more impressions and clicks, but if it pushes ACoS above your break-even level, those extra sales cost more than they earn.

Last reviewed 30 September 2026.

Sources: Amazon Ads: What is ACOS?