Work out gini coefficient instantly with clear inputs, formula shown and shareable results.
The Gini coefficient is twice the area between the Lorenz curve and the line of perfect equality, computed here from quintile income shares using the trapezoid rule. Zero means perfect equality and one means one person holds everything; the Palma ratio is often more intuitive.
Lorenz area
Area under the Lorenz curve = sum over quintiles of 0.2 x (Cumulative share at k + Cumulative share at k-1) / 2
Gini
Gini = 1 - 2 x Area under the Lorenz curve
Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.
Because grouping smooths the curve within each quintile. Gini from grouped data is typically a few points below the figure from individual records.
The income of the richest 20% divided by that of the poorest 40%. It moves more visibly than the Gini because it ignores the stable middle.