A/B Testing Core Web Vital (Annual) Calculator Examples
Explore worked examples of annual conversion, revenue, and ROI estimates from Core Web Vitals A/B testing results.
These worked scenarios show how test conversion rates, eligible traffic, rollout coverage, conversion value, and annual cost influence estimated rollout impact. They are illustrative estimates rather than forecasts.
Full LCP rollout for an ecommerce checkout
An ecommerce team tested a faster LCP experience and plans to deploy it to all eligible checkout sessions.
Input Summary
Annual eligible sessions
1,200,000
Control and variant conversion rates
2.5% and 2.7%
Average conversion value
$80
Rollout coverage
100%
Annual implementation cost
$20,000
Calculation Breakdown
- 1Affected sessions1,200,000 × 100%1,200,000
- 2Rate difference2.7% - 2.5%0.2 percentage points
- 3Incremental conversions1,200,000 × 0.0022,400
- 4Revenue and net benefit(2,400 × $80) - $20,000$172,000
Result Summary
Revenue and net benefit
$172,000
A/B Testing Core Web Vital (Annual) Calculator
The estimated annual revenue impact is $192,000, with a $172,000 net annual benefit and 860% ROI.
Partial INP rollout on supported devices
A product team improves INP on a component available only to supported mobile devices and expects 60% rollout coverage.
Input Summary
Annual eligible sessions
900,000
Control and variant conversion rates
3.0% and 3.15%
Average conversion value
$120
Rollout coverage
60%
Annual implementation cost
$30,000
Calculation Breakdown
- 1Affected sessions900,000 × 60%540,000
- 2Rate difference3.15% - 3.0%0.15 percentage points
- 3Incremental conversions540,000 × 0.0015810
- 4Revenue and net benefit(810 × $120) - $30,000$67,200
Result Summary
Revenue and net benefit
$67,200
A/B Testing Core Web Vital (Annual) Calculator
The estimated annual revenue impact is $97,200, net annual benefit is $67,200, and ROI is 224%.
CLS change with no positive conversion difference
A publisher reduces layout shift but the test variant converts slightly below the control on the selected conversion event.
Input Summary
Annual eligible sessions
2,000,000
Control and variant conversion rates
1.8% and 1.75%
Average conversion value
$25
Rollout coverage
100%
Annual implementation cost
$15,000
Calculation Breakdown
- 1Rate difference1.75% - 1.8%-0.05 percentage points
- 2Incremental conversions2,000,000 × -0.0005-1,000
- 3Annual revenue impact-1,000 × $25-$25,000
- 4Net benefit-$25,000 - $15,000-$40,000
Result Summary
Net benefit
-$40,000
A/B Testing Core Web Vital (Annual) Calculator
The entered values produce an estimated -$40,000 net annual benefit and -267% ROI.
How to Read Your Results
Conversion-rate difference is an absolute percentage-point change, not a relative lift.
Incremental conversions are estimated over one year for sessions covered by the rollout.
Annual revenue impact is calculated before annual implementation costs.
Net annual benefit can be negative if revenue impact does not exceed costs.
ROI is net annual benefit divided by annual implementation cost; it is most meaningful when the test result is credible.
Assumptions & Important Notes
- Each example assumes the observed test difference persists during the year.
- Average conversion value is assumed to be constant for the affected audience.
- The examples use revenue or conversion value, not profit, unless the entered value is already profit-based.
- No adjustment is made for confidence intervals, seasonality, or additional unlisted costs.
Related Examples
Frequently Asked Questions
Can I use these examples for LCP, INP, and CLS tests?
Yes. The calculation method is the same because it uses the measured conversion result. Select the metric that provides the experiment context.
Why does 60% rollout reduce the estimate?
Only 60% of annual eligible sessions are assumed to receive the variant, so only those sessions can generate the estimated conversion change.
Can annual revenue impact be negative?
Yes. It is negative when the entered variant conversion rate is below the control rate, producing estimated lost conversions.
Should average conversion value be average order value?
It can be, but it may also be lead value, subscription value, or another consistent value per conversion. Use the measure relevant to the decision.
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