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Lognormal Distribution Calculator

A lognormal distribution is a continuous probability distribution of a random variable whose natural logarithm is normally distributed.

Mean of the natural logarithm of the variable.

Standard deviation of the natural logarithm of the variable (must be positive).

Calculated Result
Mean: 1.649 (Median: 1)

Lognormal Metrics

Distribution Mean

1.649

Distribution Median

1

Distribution Mode

0.368

Standard Deviation

2.161

Calculation Breakdown

  1. Mean (Expected Value) FormulaE(X) = exp(μ + σ²/2) = exp(0 + 1²/2) = 1.649.
  2. Geometric Median FormulaMedian = exp(μ) = exp(0) = 1.
  3. Mode (Peak Probability Density)Mode = exp(μ - σ²) = exp(0 - 1²) = 0.368.

Skewed Central Tendencies for Lognormal (μ = 0, σ = 1)

Interactive visualization based on your current inputs

Value
0.00.51.11.62.2Mode (Peak Density)Median (50th Percentile)Mean (Expected Value)Standard DeviationMetricValue

What Is the Lognormal Distribution Calculator?

A lognormal distribution calculator evaluates central tendency and dispersion for positive-valued right-skewed variables.

How Does the Lognormal Distribution Calculator Work?

Applies exponentiated moment-generating equations from underlying Gaussian variables.

Lognormal Distribution Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

Mean = exp(μ + σ²/2) · Median = exp(μ) · Mode = exp(μ - σ²)

Converts logarithmic parameters into real arithmetic values through exponentiation.

How to Use the Lognormal Distribution Calculator

  1. Input log-scale location parameter μ and scale parameter σ.

Step-by-Step Example Calculation

Standard parameters μ = 0, σ = 1

Input Values:

mu:0
sigma:1

Understanding Your Result

Shows true arithmetic mean, geometric median, peak probability mode, and standard deviation.

Factors That Affect the Result

  • Scale parameter σ dictates rightward skewness and disparity between mode and mean.

When Should You Use This Calculator?

  • Quantitative finance asset returns, biological incubation periods, and geological mineral concentrations.

Assumptions & Limitations

  • Applies strictly to positive continuous random variables.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard mathematical lognormal parametric formulations.

Explore more tools and calculators in Statistics Calculators