Lorenz Curve Calculator
Calculate Lorenz curve coordinates showing cumulative income share versus cumulative population share.
Bottom 20% Share (%)
5.0000
Bottom 20% Share (%) vs Income 1 (lowest)
Formula
## How to Calculate the Lorenz Curve ### Method 1. Sort incomes from lowest to highest 2. Calculate cumulative population share: 20%, 40%, 60%, 80%, 100% 3. Calculate cumulative income share at each point 4. Plot cumulative income share (y) vs. cumulative population share (x) The 45-degree diagonal represents perfect equality. The Lorenz curve bows below; the area between the diagonal and the curve (relative to the total area below the diagonal) is the Gini coefficient.
Exemplo Resolvido
Five people earn 10, 20, 30, 40, 100.
- 01Total income = 200
- 02Bottom 20%: 10/200 = 5%
- 03Bottom 40%: 30/200 = 15%
- 04Bottom 60%: 60/200 = 30%
- 05Bottom 80%: 100/200 = 50%
- 06Top 20% earns 100/200 = 50% of total income
Perguntas Frequentes
What does the Lorenz curve show?
It visualizes the distribution of income (or any quantity) across a population. Each point shows what cumulative share of income is held by the bottom x% of the population. A deeper bow below the diagonal means more inequality.
How is the Gini coefficient related to the Lorenz curve?
The Gini coefficient = A / (A + B), where A is the area between the equality line and the Lorenz curve, and A + B is the total area under the equality line (0.5). So Gini = 2A.
Can two distributions have the same Gini but different Lorenz curves?
Yes. If two Lorenz curves cross, they can enclose the same total area with the diagonal but have different shapes. This is why the full Lorenz curve is more informative than the single Gini number.
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