Gini Coefficient
Calculate the Gini coefficient from income distribution data to measure wealth inequality. Free online calculator with Lorenz curve visualization and detailed interpretation.
About This Calculator
The Gini coefficient, also known as the Gini index, is a powerful statistical measure used to quantify income or wealth inequality within a population. Developed by Italian statistician Corrado Gini in 1912, it has become the standard metric for measuring economic inequality used by the World Bank, United Nations, and governments worldwide. The coefficient ranges from 0 (perfect equality where everyone has the same income) to 1 (perfect inequality where one person holds all the wealth).
Our Gini coefficient calculator works by analyzing a comma-separated list of income or wealth values. The data is sorted in ascending order, and the Gini coefficient is computed using the formula: G = (2 x Σ(i x yi)) / (n x Σyi) - (n + 1) / n, where yi are the sorted values, i is the rank, and n is the number of observations. The calculator also generates a Lorenz curve visualization that plots the cumulative income share against the cumulative population share, providing an intuitive graphical representation of inequality.
The Lorenz curve is a central concept in understanding the Gini coefficient. The 45-degree diagonal line on the chart represents perfect equality. The actual Lorenz curve shows how much income is earned by each population percentile. The farther the Lorenz curve is from the diagonal, the higher the inequality. The Gini coefficient mathematically represents the area between the Lorenz curve and the equality line divided by the total area under the equality line.
Regional Notes
India: India's Gini coefficient is approximately 0.35 (World Bank, 2019), reflecting moderate-to-high income inequality driven by urbanization and the gap between rural and urban incomes. The government tracks this through NSSO survey data and uses it for policy planning.
United States: The US Gini coefficient was 0.49 in 2021 (US Census Bureau), among the highest in developed nations. This reflects significant wealth concentration at the top, with the top 10% holding over 70% of total wealth.
United Kingdom: The UK's Gini coefficient is approximately 0.35 (ONS, 2021), similar to the OECD average. Income inequality in the UK has remained relatively stable over the past decade, though regional disparities between London and other parts of the country persist.
Frequently Asked Questions
What is the Gini coefficient?
The Gini coefficient, also called the Gini index, is a statistical measure of income or wealth inequality within a population. It ranges from 0 (perfect equality, where everyone has the same income) to 1 (perfect inequality, where one person has all the income). Developed by Italian statistician Corrado Gini in 1912, it is widely used by the World Bank, United Nations, and governments worldwide to track income distribution.
How is the Gini coefficient calculated?
The Gini coefficient is calculated from income data sorted in ascending order. The formula is G = (2 x Σ(i x yi)) / (n x Σyi) - (n + 1) / n, where yi are the sorted income values, i is the rank (1 to n), and n is the number of observations. This produces a value between 0 and 1 that represents the area between the Lorenz curve and the line of equality, divided by the total area under the line of equality.
What does a Gini coefficient of 0.4 mean?
A Gini coefficient of 0.4 indicates relatively high income inequality. Most developed economies have Gini coefficients between 0.25 and 0.40. For context, the United States had a Gini coefficient of approximately 0.49 in 2021, while many European countries like Germany (0.32) and Sweden (0.30) have lower inequality. India's Gini coefficient is around 0.35, and the United Kingdom is approximately 0.35.
Can the Gini coefficient be negative?
No, the Gini coefficient can never be negative. Since the numerator and denominator of the Gini coefficient formula both involve positive income values and cumulative shares, the result is always between 0 and 1. A value of 0 represents perfect equality, and values approach 1 as inequality increases.
What is the Lorenz curve?
The Lorenz curve is a graphical representation of income or wealth distribution. It plots the cumulative percentage of total income received against the cumulative percentage of the population, ordered from poorest to richest. The 45-degree diagonal line represents perfect equality. The Gini coefficient measures the area between the Lorenz curve and this equality line — the larger the gap, the higher the inequality.
What is a good Gini coefficient?
A Gini coefficient below 0.25 is considered low inequality, 0.25-0.30 is moderate, 0.30-0.40 is relatively high, 0.40-0.50 is high, and above 0.50 is very high inequality. Most developed nations aim for coefficients between 0.25 and 0.35, which balance economic incentives with social equity. Countries with coefficients above 0.45 often face significant social and political challenges related to wealth concentration.
How can I use the Gini coefficient calculator?
Enter a comma-separated list of income or wealth values representing your population. For example, to analyze income inequality in a group of 10 people, enter their incomes as: 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000. The calculator will compute the Gini coefficient, display the Lorenz curve, and provide an interpretation of the inequality level.
What is the difference between Gini coefficient and Gini index?
The Gini coefficient and Gini index refer to the same concept expressed on different scales. The Gini coefficient is a decimal value between 0 and 1 (e.g., 0.35), while the Gini index is the coefficient multiplied by 100, expressed as a percentage (e.g., 35%). Both are used interchangeably in economics and social science literature, with the World Bank typically reporting the Gini index as a percentage.