Gini Coefficient Calculator
Measure income inequality within a population using the Gini coefficient. Use it when comparing wealth distribution across regions, countries, or demographic groups.
About this calculator
The Gini coefficient is a statistical measure of income or wealth distribution, ranging from 0 (perfect equality) to 1 (perfect inequality). It is derived from the Lorenz curve, which plots the cumulative share of income received against the cumulative share of the population. The simplified formula used here is: Gini = (equalShare − actualShare) / equalShare. A value near 0 means income is distributed almost uniformly, while a value approaching 1 indicates extreme concentration of income among a few. Economists, policymakers, and researchers use this metric to track inequality trends over time, compare nations, and evaluate the effectiveness of redistribution policies. It is important to note that this formula provides a segment-level approximation; the full Gini index typically requires integrating the area between the line of equality and the Lorenz curve.
How to use
Suppose a country has a total income of $1,000,000. In a perfectly equal society, each quintile (20% of the population) would receive $200,000 — this is the equalShare. However, the bottom quintile actually receives only $80,000 — this is the actualShare. Applying the formula: Gini = (200,000 − 80,000) / 200,000 = 120,000 / 200,000 = 0.60. A Gini coefficient of 0.60 indicates significant income inequality, meaning the bottom 20% receives far less than their equal share. Repeat this calculation across all quintiles to build a full picture of the distribution.
Frequently asked questions
What does a Gini coefficient of 0 vs 1 mean in practice?
A Gini coefficient of 0 represents perfect equality, where every person or household earns exactly the same income. A coefficient of 1 represents perfect inequality, where a single entity earns all the income and everyone else earns nothing. In reality, most countries fall between 0.25 and 0.65. Scandinavian nations typically score around 0.25–0.30, while highly unequal economies can exceed 0.55. These benchmarks help contextualize any value you calculate.
How is the Gini coefficient used to compare income inequality between countries?
Analysts plot each country's Gini coefficient on a standardized scale, allowing direct comparisons regardless of currency or population size. International organizations like the World Bank and OECD publish annual Gini estimates to track whether inequality is rising or falling. A higher Gini score generally correlates with weaker social mobility, higher poverty rates, and greater political instability. Comparing Gini values over multiple years for the same country reveals whether redistribution policies — such as progressive taxation or social transfers — are working. However, the Gini should always be paired with other indicators for a complete picture.
Why does the Gini coefficient not fully capture wealth inequality?
The Gini coefficient measures the relative distribution of income or wealth but ignores the absolute levels involved. Two countries can share the same Gini score yet have vastly different standards of living if their average incomes differ greatly. It also treats gains at different points of the distribution equally, so it can miss extreme concentration at the very top. Additionally, the index is sensitive to how income is defined — whether it includes capital gains, government transfers, or in-kind benefits can shift results significantly. Supplementing the Gini with metrics like the Palma ratio or income share of the top 1% provides a more complete inequality analysis.