What to remember
- Use the same segment, period and unit.
- Index BDI and CDI to a base of 100.
- Treat MOI as the Calc convention, not a universal standard.
- Investigate distribution, price, competition and demand before allocating.
Calculate BDI and CDI on one reference
BDI = (segment brand-sales share ÷ segment population share) × 100. CDI replaces brand sales with category sales. A score of 100 means presence proportional to the population reference.
Another denominator such as accounts or households is possible if it is named and applied consistently.
Add MOI without overclaiming
In the audited Calc calculation, MOI = CDI ÷ BDI and is not computable when BDI is zero. With 10% population, 8% brand sales and 15% category sales, BDI = 80, CDI = 150 and MOI = 1.875.
High CDI and low BDI may indicate a strong category where the brand under-indexes. They do not identify whether distribution, price, preference, competition or data quality is responsible.
| Input | Value | Calculation | Result |
|---|---|---|---|
| Regional population | 10% | Reference | 10% |
| Brand sales | 8% | 8 ÷ 10 × 100 | BDI 80 |
| Category sales | 15% | 15 ÷ 10 × 100 | CDI 150 |
| MOI signal | - | 150 ÷ 80 | 1.875 |
Use quadrants as investigation priorities
BDI and CDI above or below 100 create four descriptive situations. High CDI and low BDI justify investigating underperformance, not automatically raising spend.
Review availability, distribution, pricing, communication, segments, profitability and competitor response.
Retain units and limits in the file
The primary editorial connection is Calc for the calculation, without proving public runtime. Grid may host market trade-offs as an editorial target without presumed synchronisation.
Retain source data, period, denominator, formulas, results, assumptions and the testable action.
Frequently asked questions
What does BDI above 100 mean?
The brand over-indexes in the segment relative to the chosen reference. It does not prove profitability.
Does high MOI prove an opportunity?
No. It is a high CDI/BDI ratio under the Calc convention and calls for causal and economic investigation.
Can regions of different sizes be compared?
Yes when shares use the same denominator, period and comparable evidence.
Full sources
- Marketing Metrics chapter on BDI and CDI, PDFComplete source available online · Read the complete source
- Circana, BDI definition and calculationComplete source available online · Read the complete source
- SRDS, BDI/CDI calculatorComplete source available online · Read the complete source