Before & after review
Did the change
help people take action?
Compare useful outcomes alongside traffic. Understand what changed, and what to investigate next.
Use the same definition.
Choose one goal and report scope. Count sessions containing that goal, not the number of event triggers.
Make the periods fair.
Use equal windows and consistent filters. Note seasonality, campaign mix and tracking changes.
Read the whole picture.
Check the rate, total outcomes and costs together. This is a comparison, not a causal test.
Bring your numbers.
Use your analytics report. Leave optional values blank when unknown; enter 0 only for a measured zero.
These calculations run in your browser. Values are kept here only when you select “Save in this browser.” They are not sent to an analytics service by this calculator.
| Measure | Before | After |
|---|
Cost per converting session is not customer acquisition cost. Revenue ÷ promotion spend is not profit. The calculator does not deduplicate customers, adjust attribution or test statistical significance.
Make the numbers easier to read.
- Step 1
Match the periods
Use equal windows and the same page and channel.
- Step 2
Enter comparable counts
Use sessions and sessions containing the goal.
- Step 3
Record the decision
Note the change, uncertainty and next action.
A rate tells you how often.
Sessions with the goal ÷ total sessions × 100
If 30 out of 1,000 sessions included a request, the observed rate is 3%.
A point change is the gap.
New rate − previous rate
Going from 3% to 4% is +1 percentage point, or a 33.3% relative increase. Neither proves the page change caused it.
Where do I find sessions with a goal in GA4?
Use a report or exploration scoped to the same sessions and the chosen key event. GA4 distinguishes event counts from session key event rate. Do not paste the total number of key events into “Sessions with the goal”: one session may trigger an event several times.
See Google’s definitions for sessions and session key event rate.
What if the baseline is zero or the counts are small?
A zero baseline rate makes a relative percentage increase undefined. A period with no sessions has no conversion rate. The tool labels these values “Not available.” Fewer than 20 goal sessions in either period triggers a caution; this is a simple review prompt, not a statistical confidence threshold.
Can I use a different currency?
This version labels money values in USD. Do not mix currencies or enter another currency under the USD label. You can leave the optional spend and revenue fields empty and still compare session counts and rates.
Reference: Google Analytics traffic-source scope. Matching report scope matters when comparing acquisition and outcomes.