What is the Lerner Index?

The Lerner Index measures a firm's market power by comparing price to marginal cost. It is calculated as (Price - Marginal Cost) / Price. A higher index indicates more pricing power and less competition.

How do I use the Lerner Index Calculator?

Enter the price of your product and the marginal cost of producing it. The calculator will compute the Lerner Index, showing the percentage markup over marginal cost. This helps assess how much control you have over pricing.

What does a Lerner Index of 0 mean?

A Lerner Index of 0 indicates perfect competition, where price equals marginal cost. This means the firm has no pricing power and is a price taker in the market.

Finance

Instant, private, and free

Lerner Index Calculator.

Calculate the Lerner index from price and marginal cost.

On-device calculationNo signup

Set your values

Results update as you type.

02 / ANSWER

Price

Marginal cost

Lerner index

0.4

Lerner index

40%%

FAQs

How does the lerner index calculator work?

Enter the requested values to receive a deterministic result. No live market, tax, or jurisdiction data is inferred.

Related Calculators

Profitability Index CalculatorCalculate profitability index from explicit inputs with documented assumptions and instant debounced results.EMV CalculatorCalculate emv from explicit user inputs with transparent assumptions and instant, debounced results.EOQ CalculatorCalculate eoq from explicit user inputs with transparent assumptions and instant, debounced results.EPS CalculatorCalculate eps from explicit user inputs with transparent assumptions and instant, debounced results.FFO CalculatorCalculate ffo from explicit user inputs with transparent assumptions and instant, debounced results.Free Float CalculatorCalculate free float from explicit user inputs with transparent assumptions and instant, debounced results.

Cite this calculator

Canonical URL: https://mathify.one/en/finance/lerner-index

Cite as: Mathify. (n.d.). Lerner Index Calculator. https://mathify.one/en/finance/lerner-index

Use Cases

Assess Market Power

Businesses and economists use the Lerner Index to evaluate how much pricing power a firm has relative to its costs. A higher index suggests stronger market dominance.

Example: If a firm sells at $100 with a marginal cost of $60, the Lerner Index is 0.4, indicating moderate pricing power.

Competitive Analysis

Compare your Lerner Index with competitors to understand your position in the market. This can inform pricing strategies and competitive responses.

Example: If your index is 0.3 and a competitor's is 0.5, they have more pricing power, possibly due to brand strength or product differentiation.

Frequently Asked Questions

What is the Lerner Index?: The Lerner Index measures a firm's market power by comparing price to marginal cost. It is calculated as (Price - Marginal Cost) / Price. A higher index indicates more pricing power and less competition.
How do I use the Lerner Index Calculator?: Enter the price of your product and the marginal cost of producing it. The calculator will compute the Lerner Index, showing the percentage markup over marginal cost. This helps assess how much control you have over pricing.
What does a Lerner Index of 0 mean?: A Lerner Index of 0 indicates perfect competition, where price equals marginal cost. This means the firm has no pricing power and is a price taker in the market.

Tips & Common Mistakes

Tips

Ensure you use the actual marginal cost, not average cost, for accurate results.
A Lerner Index close to 1 indicates near-monopoly pricing power, while 0 means perfect competition.
Use the index to benchmark your pricing strategy against industry norms.
Remember that the Lerner Index is a snapshot; it can change with market conditions and cost structures.

Common Mistakes to Avoid

Using average cost instead of marginal cost, which can skew the index.
Confusing the Lerner Index with profit margin; it specifically measures pricing power relative to cost.
Ignoring that a high Lerner Index may attract regulatory attention if it indicates monopoly power.

Last updated: August 13, 2026