Gini Coefficient Calculator
Calculate the Gini coefficient — a measure of income or wealth inequality — from a population income distribution using the standard trapezoidal method.
Results
What is it?
The Gini coefficient measures income or wealth inequality on a scale of 0 (perfect equality — everyone has the same income) to 1 (perfect inequality — one person has all income). It equals one minus twice the area under the Lorenz curve. The Palma ratio compares the top 20% income share to the bottom 40% — a simpler inequality measure.
How to use
Enter the income share (as a percentage of total national income) held by each income quintile. The five quintiles must sum to 100%. World Bank and OECD publish these figures for most countries.
Example scenario
Income shares: Q1=5%, Q2=10%, Q3=16%, Q4=24%, Q5=45%. Gini ≈ 0.36. This is typical of a moderately unequal country (Brazil ≈ 0.53; Denmark ≈ 0.29; USA ≈ 0.39).
Pro tip
Gini below 0.3 is considered low inequality (Scandinavian countries). Above 0.5 is very high (some Sub-Saharan African countries). The Palma ratio is often favoured by economists as it focuses on the politically salient extremes of the distribution.