THE SHORT ANSWER

A metric is a defined measurement. A KPI is a metric selected to represent progress toward a priority objective. A target states the desired range or level, while a business outcome describes the value or condition the organization ultimately wants to change.

Give each term one job

Measurement vocabulary
TermMeaningExample
MetricA defined quantityQualified leads
KPIA metric representing a priority objectiveCustomer acquisition cost for the growth plan
TargetA desired value or operating rangeAllowable CAC under stated economics
Leading indicatorAn earlier signal linked to a later outcomeProduct-qualified trial activity
Lagging indicatorA result visible after activity maturesRealized cohort contribution
Business outcomeThe valuable condition the organization seeksSustainable profitable growth

A formula needs a scope

Conversion rate can use sessions, users or eligible visitors. CAC can include media alone or a wider acquisition cost. AOV can include or exclude tax, shipping and refunds. ROAS depends on attributed revenue and its model. Retention depends on the behaviour and time window.

Keep a metric dictionary with formula, owner, source, time basis, inclusion rules, latency and known limitations. Two teams can calculate different numbers correctly if they have answered different questions.

Connect signals to the outcome

Traffic and click-through rate can indicate whether distribution changed. Conversion and CAC can describe movement through acquisition. Revenue and retention move closer to business value. Profitability asks whether that value remains after relevant costs.

Do not label every useful diagnostic a KPI. A small KPI set can be supported by many temporary diagnostic metrics when a problem needs investigation.

Evidence & context: Google Analytics Help · Google Analytics Help

Use fewer metrics with stronger decision rights

  1. Name the objective and decision.
  2. Choose one primary outcome measure.
  3. Add the minimum leading and diagnostic signals needed to explain it.
  4. Add guardrails for quality, economics and customer experience.
  5. Remove metrics with no owner or response.

For commerce-specific definitions, use E-commerce Analytics. For acquisition ratios, use CAC, CPA, CPL and ROAS Explained.

Sources & further reading

  1. Understand user metrics

    Google Analytics Help. Official definitions for total, active, new and returning users. Identity limits and configuration can affect interpretation.

  2. Ecommerce purchases report

    Google Analytics Help. Official definitions for item-level commerce metrics. Revenue fields have different inclusions, so teams must document the field they use.

  3. API dimensions and metrics

    Google Analytics. Official GA4 reporting definitions checked 13 September 2026, including session source, medium, referral and landing-page dimensions. Attribution remains limited to observable interactions.

Examples and exercises are illustrative unless attributed to a source. No independent expert review is claimed.

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