Amazon CTR Calculator and A/B Test Planner | Aspi

Free tools for Amazon sellers

CTR calculator.

Work out your click-through and conversion rates, see how much traffic a hero image test needs, and check whether a result is real. The calculators run in your browser, and nothing you type into them is sent anywhere.

Tool 1

CTR and conversion calculator

Enter impressions and clicks for CTR. Add orders and price to see conversion rate and what each 1,000 impressions are worth. Optionally enter a new CTR to see what the change would add.

Tool 2

Hero image test planner

Before you test, find out how many impressions each version needs for a difference of the size you care about to show up. Small lifts on low CTRs take a lot of traffic.

Tool 3

Is my result real?

Enter impressions and clicks for two versions. You get the difference, how sure you can be about it, and a plain-language verdict.

Variant A (current)
Variant B (new)

How to use these honestly

  • Test one change at a time, over the same days, and decide the sample size before you start. Stopping the moment a result looks good produces false wins.
  • Clicks and sessions are not the same thing. The calculators treat "clicks" as whatever your report gives you, whether search-term clicks or detail page sessions. Use one consistently.
  • Amazon's own Manage Your Experiments does its own statistics. Use the checker for manual tests, ad creative, and sanity-checking other numbers.

More on measuring and testing: how to measure CTR on Amazon, A/B test statistical significance, A/B testing images, and the full CTR, CVR and testing topic.

The formulas

  • CTR = clicks ÷ impressions
  • Conversion rate = orders ÷ clicks
  • Impressions needed per variant = (zα/2√(2p̄(1−p̄)) + zβ√(p1(1−p1) + p2(1−p2)))² ÷ (p2−p1)², the standard two-proportion sample-size formula, where p1 is your CTR, p2 the CTR after the lift, and p̄ their average
  • Result check = a two-proportion z-test with a pooled standard error, and a confidence interval for the difference using the unpooled standard error
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