Competitive Price Index in FMCG: How to Compare Like-for-Like Prices

TL;DR

A competitive price index expresses a brand’s price relative to a defined competitor or reference price. In a simple product-level calculation, Brand Price ÷ Reference Price × 100 gives an index of 100 when prices match, above 100 when the brand is more expensive and below 100 when it is less expensive. The direction depends on which price is in the numerator, so every report must state its convention. A useful FMCG comparison also matches product type, pack size, channel, location, period and promotional condition. An index describes relative price position; it does not prove what demand or market share will do next.

What Is a Competitive Price Index in FMCG?

A competitive price index compares the price of a product or group of products with a clearly defined market reference. It gives commercial and revenue management teams a consistent way to describe whether their products are priced above, at or below selected alternatives.

A price index is especially useful in FMCG when the same category contains multiple brands, pack sizes and independent retail outlets. However, the number is only meaningful when the reference and product basket remain comparable. A premium pack should not be silently compared with a basic alternative as if the products were identical.

How Do You Calculate a Competitive Price Index?

The simplest product-level calculation uses:

Competitive Price Index = Brand Price ÷ Reference Price × 100

In this guide the brand is the numerator and the competitor is the reference denominator. An index of 120 means the brand price is 20% higher than the selected reference price. An index of 90 means it is 10% lower. A different reporting convention may reverse the ratio, so the numerator must always be named.

If the brand costs TRY 48 and an equivalent competitor pack costs TRY 40 in the same market and period, the index is 48 ÷ 40 × 100 = 120. This is a price-relative calculation, not a measure of price elasticity or an automatic recommendation to lower the price.

Worked Example: Comparing Two FMCG Products

Consider a hypothetical category with two matched pack-size comparisons. The observed prices below are examples only, not TrendBox client data or live retailer prices. Each line uses the same pack size, retail channel and observation period for brand and reference.

The 500 ml pack has an index of 120, while the 1 litre pack has an index of 90. The brand is more expensive for the smaller matched pack and less expensive for the larger matched pack. Reporting only one “brand price index” without a product-basket definition would hide that important difference.

What Does an Index Above or Below 100 Mean?

With brand price divided by competitor price, the interpretation is:

• 100: Both prices are equal on the selected comparison basis.
• Above 100: The brand is priced at a premium relative to the reference.
• Below 100: The brand is priced below the selected reference.
• A change from 105 to 115: The relative premium has widened by 10 index points, not necessarily by 10% in price.

A 120 index does not automatically mean a brand is overpriced. Product positioning, quality, pack format, shopper expectations and margin objectives may support a premium. The index shows the difference; deciding what to do requires commercial context.

How Do You Compare Different Pack Sizes?

When packs differ, first normalize the price to a suitable physical unit such as price per litre or kilogram. For example, a 500 ml pack priced at TRY 42 costs TRY 84 per litre, while a competing 1 litre pack priced at TRY 75 costs TRY 75 per litre. On a price-per-litre basis, the relative index is 84 ÷ 75 × 100 = 112.

This calculation controls for package quantity but does not make the products identical. A single-use format and family-size pack can serve different purchase occasions. Keep both pack price and unit price visible when evaluating price architecture, and do not ignore multipacks or promotional bonus contents.

How Do You Build a Weighted Competitive Price Index?

A product-level price relative tells the story for one matched pair. A multi-SKU price index needs a fixed comparison set and an explicit aggregation method. One simple illustrative approach is to calculate each product’s price relative and take a weighted average using preselected, consistent product weights.

For example, suppose the two product price relatives in the table are 120 and 90, and the analysis fixes weights at 60% for the 500 ml format and 40% for the 1 litre format. The illustrative weighted average of price relatives is (120 × 0.60) + (90 × 0.40) = 108. The result describes the selected fixed-weight basket, not every category product or market outlet.

Different weighting conventions can produce different index values. Weights might reflect a fixed reference basket, category sales or other defined commercial importance. A simple average should not be described as a universal industry formula or as TrendBox’s proprietary calculation method.

Why Must the Reference Basket Stay Comparable?

If the competitor set, outlet mix, period or pack sizes change between reports, the index may move even when no SKU price changes. A brand can appear to become more expensive because the reference shifted toward lower-priced competitor products, or because data now includes different outlet types.

For period-over-period comparisons, retain a stable reference basket where possible, document additions or removals and distinguish like-for-like changes from changes caused by weights or assortment. If a new SKU enters the category, report its inclusion explicitly rather than quietly rewriting the old comparison.

Should You Use Shelf Price or Realized Selling Price?

Shelf price is the displayed retail price observed at a particular time. Realized selling price reflects transactions and may be calculated as net sales value divided by units for a consistent SKU. Promotions, customer discounts and outlet sales mix can make the two measures differ.

An index built from shelf observations and one built from realized transaction prices do not answer precisely the same question. Define the price basis and treatment of returns, discounts and taxes before comparing results. Avoid combining a displayed shelf price from one product with an average transaction price from another without explanation.

How Do Promotions Affect the Competitive Price Index?

A temporary price promotion can move a product’s index sharply for a short period. If the reference product is on promotion while your product is not, your relative premium may widen even though your own shelf price is unchanged.

Report promotional and regular periods separately where helpful. For an evaluation of price position, compare the same stores and dates or use a consistent rule for averaging observations. To understand actual demand response, analyze sales, distribution and promotion exposure; price ratios alone are insufficient.

Can a Competitive Price Index Explain Market Share Loss?

Not by itself. A higher relative price can be a useful hypothesis for a market share decline, but distribution loss, weaker availability, changes in pack mix and category growth may also influence share. A price index is a descriptive position measure.

A practical investigation starts by locating where the index changed, checking the exact matched SKUs and promotions, then reviewing value and volume share, sales velocity and distribution in comparable outlets. For related interpretation, see FMCG market share analysis.

What Is the Difference Between a Price Index and Price Elasticity?

A competitive price index compares price levels between products or baskets. Price elasticity measures how quantity demanded responds to changes in price under an estimated demand relationship. An index of 120 does not imply that a 1% price increase will cause a particular change in units.

Monitoring can identify a price gap worth investigating. Elasticity analysis addresses whether and to what extent demand responds after other important factors are considered. Those are separate analytical tasks.

How Can FMCG Teams Use Competitive Price Index Results?

• Monitor the premium or discount of matched priority SKUs.
• Identify regional and outlet-group differences in relative price position.
• Review price ladders across pack sizes and variants.
• Assess whether a promotion temporarily changed competitive positioning.
• Compare relative price movements with distribution, unit sales and category share.
• Decide which price questions deserve further testing or revenue-management review.

The index should trigger a defined investigation rather than a reflex to match the cheapest competitor. Any eventual price decision should also consider costs, margin, category role and expected demand response.

How Does TrendBox Support Relative Price Analysis?

TrendBox publicly lists Price Index, Price Distribution, Price Monitoring and Daily Pricing Monitor within its Price Intelligence capabilities. These features support analysis of relative positioning, observed price spreads and changing prices across the measured channel. FMCG Tracker supplies related market-share, distribution and velocity context.

The simple formulas here explain general price-index concepts; they are not a claim that TrendBox uses this precise fixed-weight calculation in its own product. The actual index definition, selected competitive references and price basis should be agreed for the business question. Review TrendBox’s features and price and revenue intelligence services for capability scope.

Frequently Asked Questions About Competitive Price Index

What is a competitive price index?

It is a measure of how a product or defined basket is priced relative to a chosen reference, commonly scaled to 100.

How is a competitive price index calculated?

A simple product-level method divides your price by the reference price and multiplies by 100. The reference and numerator convention must be stated.

What does an index of 120 mean?

Under the brand-price-over-reference convention, the brand is priced 20% above the selected comparable reference.

Is 100 always the best price index?

No. An index of 100 indicates parity with the reference, not an optimal price. The appropriate position depends on brand strategy and commercial objectives.

Can different pack sizes be compared?

Yes, with a relevant price-per-litre, kilogram or other standardized unit, while retaining pack-price and format context.

Does a price index show inflation?

A competitive FMCG price index compares relative product pricing. It is not automatically a consumer price index or a measure of economy-wide inflation.

Is price index the same as price elasticity?

No. The index expresses relative price levels; elasticity estimates demand response to a price movement.

Can TrendBox calculate a competitive price index?

TrendBox lists Price Index within its Price Intelligence suite. The exact benchmark, method and report scope should be confirmed for the category.

Compare the Right Prices Before Changing Them

A useful competitive price index begins with the right product matches and a transparent reference. Compare equivalent packs, keep the observation basis stable and read relative price alongside market share and sales velocity. Contact TrendBox to scope price-index and price-positioning analysis for your FMCG category.