Competitor Price ComparisonCompetitor Price Comparison › Price index
How do you calculate a competitor price index?
Divide your price by a reference price, such as the average or lowest competitor price for the same product, and multiply by 100. An index of 105 means you're 5% above the market; 95 means 5% below. For a category, average the product indexes, weighted by sales so best sellers count more.
Updated 10 November 2026 by the ScrapeWise team.
Quick picks
For a quick view
Index vs market average
One number per product.
For price-led categories
Index vs lowest price
Shows the gap to beat.
For the data behind it
ScrapeWise (our product)
Matched products and unit prices in euros.
Compared
| Reference | Formula | Tells you | Use when |
|---|---|---|---|
| Average competitor price | Your price ÷ average × 100 | Position against the market | General price positioning |
| Lowest competitor price | Your price ÷ lowest × 100 | Gap to the cheapest offer | Price-led categories |
| Key competitor | Your price ÷ their price × 100 | Position against one rival | Head-to-head strategy |
| Weighted category index | Σ (index × weight) ÷ Σ weight | Category position | Reports and targets |
A worked example
- Your price
- €3.90 for 6 × 0.5 L, which is €1.30 per litre.
- Competitors
- €1.45, €1.24 and €0.86 per litre; the average is €1.18.
- Index
- 1.30 ÷ 1.18 × 100 ≈ 110: about 10% above the market average.
Making the index reliable
- Use identical products
- Similar products make the index meaningless.
- Use unit prices
- Pack sizes distort listing prices.
- Refresh it
- A month-old index misses promotions.
Frequently asked questions
What is a price index?
Your price divided by a reference price, such as the market average, multiplied by 100. 100 means level with the market.
How do you calculate a category price index?
Calculate each product's index, then take a weighted average, using sales or revenue as weights.
What is a good price index?
It depends on strategy. Discount retailers aim below 100; premium retailers can sustain indexes above 100.
Which competitors should be in the index?
The ones your customers actually compare you with, usually three to five per category.