Gini Coefficient Calculator

Measure income inequality with the Lorenz curve areas above and below the line of equality. This page also keeps the formula, examples, FAQs, and references close by so you can check the result with confidence.

What This Gini Coefficient Calculator Helps You Do

The Gini coefficient equals the area above the Lorenz curve divided by the total area under the line of equality. Review the formula and examples below if you want to see how the result is derived.

This page is meant to give you a fast answer, but it also helps you double-check the math before you make a decision. Start with the inputs that you already know, run the calculation, and then compare the output with the formula, examples, and FAQs below so you can see whether the answer fits the situation you are modeling.

If the result looks off, the usual causes are a unit mismatch, a missing decimal, the wrong scenario, or a value that needs to be entered as a rate instead of a total. The notes on this page are designed to make those checks easy without forcing you to leave the calculator and search for context elsewhere.

  • Use the calculator first for a quick estimate.
  • Use the formula to understand how the result is built.
  • Use the examples to compare common use cases.
  • Use the references when the answer depends on a standard or assumption.

Common Checks

A quick result is useful, but the best result is one that still makes sense when you look at it a second time. If you are comparing scenarios, try changing one input at a time so you can see which variable has the biggest impact on the final answer. That makes it much easier to spot whether the calculation matches your expectations.

It also helps to keep the context of the problem in mind. A calculator can tell you the math, but you still need to decide whether the input represents a total, a rate, an average, or a category-specific assumption. When in doubt, start with a simple example from the page and scale up from there.

  • Check that every unit matches the rest of the problem.
  • Keep rates, totals, and averages separate.
  • Adjust one variable at a time when testing scenarios.
  • Use the smallest realistic input first, then scale upward.

Scenario Planning

This calculator is especially useful when you want a quick answer before you commit time, money, or effort. Try one baseline input set, then change a single number and compare the result so you can see how sensitive the answer is to that variable.

That makes the page useful for more than just arithmetic. It becomes a small decision aid that helps you compare options, test assumptions, and explain the final number with confidence when you need to share it with someone else.

units²
units²

Result

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Quick Answer: The Gini coefficient equals the area above the Lorenz curve divided by the total area under the line of equality. Review the formula and examples below if you want to see how the result is derived.

How to Calculate Gini Coefficient Calculator

  1. Enter the area above the curve: This is the area between the line of equality and the Lorenz curve.
  2. Enter the area below the curve: This is the area under the Lorenz curve.
  3. Read the coefficient: The result ranges from 0 for perfect equality to 1 for maximum inequality.

Gini Coefficient Calculator Formula

Gini coefficient = A / (A + B).
Variable Meaning Unit
A Area above the Lorenz curve and below the equality line units²
B Area below the Lorenz curve units²
Result Inequality index from 0 to 1

Worked Examples

USA - Example from the article
  • Area above the Lorenz curve: 1,200
  • Area below the Lorenz curve: 3,800

Result: 0.24

The Gini coefficient is 0.24, which indicates a moderate level of equality.

UK - More unequal distribution
  • Area above the Lorenz curve: 2,000
  • Area below the Lorenz curve: 3,000

Result: 0.40

A higher coefficient indicates more income inequality.

EU - Perfect equality check
  • Area above the Lorenz curve: 0
  • Area below the Lorenz curve: 5,000

Result: 0

Zero means a perfectly equal distribution.

How to Interpret Your Results

Range Meaning Action
Close to 0 High equality The income distribution is relatively even.
Mid-range Moderate inequality Compare the result across time or against peer countries.
Closer to 1 High inequality Review the underlying income distribution and social policy context.

Frequently Asked Questions

It measures inequality in a distribution, usually income or wealth.

It means perfect equality.

It means maximum inequality, where one person holds all the measured wealth.
Planning note: The Gini coefficient depends on how the Lorenz curve areas are estimated, so the result should be treated as an inequality indicator rather than an exact law.

References

Last reviewed: March 2026