Sturges’ Formula Calculator

Number of bins = ⌈log$_2(n)$ + 1⌉
where $n$ is the sample size
Please enter a positive number.
Number of Bins to Use:

Understanding Sturges' Rule

💡 Sturges' Rule provides a guideline for determining the optimal number of bins to use when creating a histogram. It is particularly useful when you want to visualize data distributions effectively.

Formula for Sturges' Rule

The formula for calculating the number of bins (\(k\)) is:

\[ k = \lceil \log_2(n) + 1 \rceil \] Where:
  • \(n\): Sample size (number of data points)
  • \(\lceil x \rceil\): Ceiling function, which rounds up to the nearest integer

Key Concepts

  • Data Visualization: Using an appropriate number of bins ensures your histogram effectively represents the underlying data distribution without over-smoothing or overfitting.
  • Sample Size Dependency: The number of bins increases with the sample size, reflecting finer granularity in larger datasets.
  • Ceiling Function: Ensures the number of bins is always an integer, as fractional bins are not possible in practice.

Note: Sturges' Rule assumes the data follows a normal distribution. For highly skewed or non-normal data, alternative methods (like Scott’s Rule or Freedman-Diaconis Rule) may be more appropriate.

Real-Life Applications

Sturges' Rule is widely applied in various fields to enhance data visualization:

  • Finance: Creating histograms to analyze the distribution of stock returns or risk metrics.
  • Healthcare: Visualizing patient data distributions, such as age or test scores.
  • Education: Analyzing grade distributions or survey results.

Limitations of Sturges' Rule

  • Normality Assumption: The rule is less effective for non-normal data distributions, where more advanced binning methods may be required.
  • Large Sample Sizes: For very large datasets, the bins suggested by Sturges' Rule may oversimplify the distribution.
  • Data Granularity: The rule may not work well for highly granular or categorical data, where bins need to reflect specific intervals or categories.

Python Implementation

Python Function for Sturges' Rule
import math

def sturges_rule(n):
    """
    Calculate the optimal number of bins using Sturges' Rule.

    Parameters:
        n (int): Sample size

    Returns:
        int: Number of bins
    """
    if n <= 0:
        raise ValueError("Sample size must be greater than 0.")

    return math.ceil(math.log2(n) + 1)

# Example usage
sample_size = 100
bins = sturges_rule(sample_size)
print(f"Optimal number of bins: {bins}")

R Implementation

R Function for Sturges' Rule
sturges_rule <- function(n) {
    # Check if the sample size is valid
    if (n <= 0) {
        stop("Sample size must be greater than 0.")
    }

    # Calculate the number of bins
    bins <- ceiling(log2(n) + 1)
    return(bins)
}

# Example usage
sample_size <- 100
bins <- sturges_rule(sample_size)
cat(sprintf("Optimal number of bins: %d\n", bins))

JavaScript Implementation

JavaScript Function for Sturges' Rule
/**
 * Calculate the optimal number of bins using Sturges' Rule.
 * @param {number} n - Sample size
 * @returns {number} - Number of bins
 */
function sturgesRule(n) {
    if (n <= 0 || isNaN(n)) {
        throw new Error("Sample size must be greater than 0.");
    }

    // Calculate the number of bins
    return Math.ceil(Math.log2(n) + 1);
}

// Example usage
const sampleSize = 100;
const bins = sturgesRule(sampleSize);
console.log(`Optimal number of bins: ${bins}`);

Further Reading

Explore the following resources to deepen your understanding of data binning and histogram optimization:

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Senior Advisor, Data Science | [email protected] | + posts

Suf is a senior advisor in data science with deep expertise in Natural Language Processing, Complex Networks, and Anomaly Detection. Formerly a postdoctoral research fellow, he applied advanced physics techniques to tackle real-world, data-heavy industry challenges. Before that, he was a particle physicist at the ATLAS Experiment of the Large Hadron Collider. Now, he’s focused on bringing more fun and curiosity to the world of science and research online.