Sample Excess Kurtosis from 4th Moment and Variance Calculator
Excess kurtosis = m₄ / σ⁴ − 3.
Compute the excess kurtosis of a distribution from its centred fourth moment m₄ = E[(X − μ)⁴] and the variance σ²: excess_kurtosis = m₄ / σ⁴ − 3. Subtracting 3 makes a normal distribution have an excess kurtosis of 0. > 0 = leptokurtic (heavy tails); < 0 = platykurtic (light tails).
How to use this calculator
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Formula
γ₂ = m₄ / σ⁴ − 3.
In depth
Compute the excess kurtosis of a distribution from its centred fourth moment m₄ = E[(X − μ)⁴] and the variance σ²: excess_kurtosis = m₄ / σ⁴ − 3. Subtracting 3 makes a normal distribution have an excess kurtosis of 0. > 0 = leptokurtic (heavy tails); < 0 = platykurtic (light tails).
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