Herfindahl-Hirschman Index (HHI) Calculator for Highly Competitive Market (Equal Shares)
Represents a highly competitive market where four firms each hold an equal 25% market share.
Calculate market concentration using the Herfindahl-Hirschman Index (HHI) based on up to four firms' market shares. Enter your Firm 1 Market Share (%), Firm 2 Market Share (%), Firm 3 Market Share (%), Firm 4 Market Share (%) to get an instant herfindahl-hirschman index (hhi). Formula: pow(s1, 2) + pow(s2, 2) + pow(s3, 2) + pow(s4, 2).
Herfindahl-Hirschman Index (HHI)
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How It Works
How It Works
The Herfindahl-Hirschman Index (HHI) measures how concentrated a market is. It does this by squaring each firm’s market share and then adding those squared values together.
Because each market share is squared, larger firms have a much bigger impact on the final number. This makes the index especially sensitive to dominant companies in the market.
- Enter each firm's market share as a whole number (e.g., 25 for 25%).
- Each market share is squared (multiplied by itself).
- All squared values are added together.
- The final result is a single HHI value on a 0–10,000 scale.
Understanding the Results
The HHI result shows how competitive or concentrated a market is. A lower number means the market is more competitive, while a higher number means fewer firms control more of the market.
If one company has 100% of the market, the HHI would be 10,000 (100²). If market share is evenly split among many firms, the HHI will be much lower.
- HHI below 1,500 suggests a competitive market.
- HHI between 1,500 and 2,500 suggests moderate concentration.
- HHI above 2,500 suggests high concentration.
- Higher values mean less competition and more market dominance.
Frequently Asked Questions
What is the Herfindahl-Hirschman Index (HHI)?
The Herfindahl-Hirschman Index (HHI) is a measure of market concentration used to assess the level of competition within an industry. It is calculated by squaring the market share of each firm and summing the results. The index ranges from close to 0 (highly competitive market) to 10,000 (monopoly).
How do I enter market shares into the calculator?
Enter each firm's market share as a whole number percentage (for example, enter 25 for 25%). You can enter up to four firms' market shares. If there are fewer than four firms, simply enter 0 for the unused fields.
What does the HHI result mean?
An HHI below 1,500 typically indicates a competitive market, 1,500 to 2,500 suggests moderate concentration, and above 2,500 indicates high concentration. For example, if four firms each have 25% market share, the HHI would be 2,500, reflecting moderate concentration.
When should I use the HHI calculator?
Use this calculator when analyzing industry competition, evaluating potential mergers, or conducting market research. Regulators such as the U.S. Department of Justice often use HHI to assess whether mergers may reduce competition.
Do the market shares need to add up to 100%?
Ideally, the total market shares should equal 100% to accurately represent the entire market. However, the calculator will still compute an HHI even if the total is slightly above or below 100%, though the result may not fully reflect actual market concentration.
Why are the market shares squared in the formula?
Squaring the market shares gives more weight to larger firms, reflecting their greater influence on market concentration. For example, a single firm with 60% market share contributes much more to the HHI than several small firms with 5% each.
Disclaimer
This financial calculator provides estimates only. Actual results may vary. Consult a qualified financial advisor for personalized guidance. Disclaimer.