Relative change
also called Relative period-over-period changeDelta percent
Definition
How large a period-over-period change is relative to the comparison period.
Scope, grain and dimensions
- Grain
- One value per metric per pair of date ranges, or one per breakdown row in a period-over-period breakdown.
- Required filters
- date_range · comparison_range
- Aggregation
- Computed once per metric per comparison. Null when the comparison value is zero, so a growth-from-nothing case returns no relative change rather than an infinity.
- Metric type
- derived metric · relative change
Data sources
Skills and analyses that use it
Skills carry the judgment; the analysis verbs do the reading.
Analysis verbs
pop_significancesignificance_checkpaid_search_overviewpaid_impression_shareweb_analytics_overviewconversions_overviewsite_health_cwv_check
Method rungs and levers
A rung tells you what a movement here can and cannot explain, read the rungs below it first.
Ask Quattr
- "How much did clicks change in percentage terms?" Simulate this →
- "What is the percent change versus last month?" Simulate this →
Caveats, freshness and failure modes
The scale is not consistent between producers, confirm which one a value came from before rendering it as a percentage.
Null when the comparison value is zero, which is correct and is not the same as a zero change.
It is a relative change, so a small absolute move on a small base produces a large value. Always pair it with the absolute change.
It says nothing about whether a change is distinguishable from noise; that is the p-value's job.
- Freshness
- varies by site, priority URLs can run nightly; most pages far less often. The collection date rides on the card rather than being assumed.
Common failure modes
- Rendering a fraction-scaled value as a percent, or a percent-scaled value as a fraction, a hundredfold error in either direction.
- Reading a large relative change on a tiny base as a meaningful result.
- Treating a null as a zero change.
Not the same as
The confusions that cause the most wrong decisions.
Relative change Conversion-rate change Compare definitions →
One is the absolute difference between two rates; this expresses a difference relative to its comparison base. On a small base the relative form can be dramatic while the absolute form is negligible.
Relative change p-value Compare definitions →
Size and evidence are different questions. A large relative change on thin data and a small one on heavy data routinely carry opposite p-values.
Watch this metric read in a real run
All runs →
2 min 5 secTraffic more than halved in six months. Nobody could say why.Search Console · Anomaly investigator◐Recreated from an anonymized session
3 min 4 secThe fix shipped. Traffic rose. Now two teams want the credit.Lighthouse + Search Console + Rank tracking · Significance referee · Cross domain correlator◐Recreated from an anonymized session
2 min 26 secConversion rate fell 7.5%. The number is real. The panic is not.Web analytics · Significance referee◐Recreated from an anonymized session
2 min 2 secSomething went right this quarter. Now prove it before you say it out loud.Rank tracking + Search Console · SERP feature watch · Significance referee◐Recreated from an anonymized session
2 min 18 secThe deck is due tomorrow. The numbers live in five places.Search Console + Rank tracking + AI visibility + Web analytics + Google Ads · Monthly exec review◐Recreated from an anonymized session
2 min 20 secWhere do we stand? Five questions answer it, in order.Search Console + Rank tracking + AI visibility · Monthly exec review◐Recreated from an anonymized session
Related metrics and workflows
Verification
A definition is the smallest part of this.
The measurement matters because something acts on it. Here is the rest of the showcase, in the order most people find useful.