Histogram — Visualize Data Distribution
Paste raw data, choose binning method (Sturges, Scott, Freedman-Diaconis), toggle density mode and normal overlay. Get descriptive stats and cumulative histogram.
Why This Statistical Analysis Matters
Why: Histograms reveal shape, center, spread, and outliers. The right bin count matters — too few bins hide detail; too many create noise.
How: Enter data (comma/space separated). Choose binning: Sturges (classic), Scott (normal-optimal), Freedman-Diaconis (robust). Toggle density for area=1 overlay.
- ●Sturges: 1+log2(n)
- ●Scott: optimal for normal
- ●F-D: robust to outliers
Customizable Histograms — Multiple Binning Methods & Normal Overlay
Paste raw data, choose binning method, toggle density mode and normal overlay. Get descriptive stats and cumulative histogram.
Real-World Scenarios — Click to Load
Data Input
100 values parsed
Histogram (Frequency) — 8 bins, width = 7.0000 + Normal N(μ,σ) overlay
Normal Curve Overlay (N(μ,σ))
Cumulative Histogram
Bin Frequency Table
| Bin | Frequency | Relative |
|---|---|---|
| 44.00 – 51.00 | 6 | 6.00% |
| 51.00 – 58.00 | 11 | 11.00% |
| 58.00 – 65.00 | 15 | 15.00% |
| 65.00 – 72.00 | 16 | 16.00% |
| 72.00 – 79.00 | 15 | 15.00% |
| 79.00 – 86.00 | 16 | 16.00% |
| 86.00 – 93.00 | 14 | 14.00% |
| 93.00 – 100.00 | 7 | 7.00% |
Calculation Breakdown
For educational and informational purposes only. Verify with a qualified professional.
📈 Statistical Insights
k = ceil(1 + log2(n)) — classic bin count
— 1926
Width = 3.49σn^(-1/3) — optimal for normal
— 1979
Width = 2×IQR×n^(-1/3) — robust
— 1981
Key Takeaways
- • A histogram displays the distribution of numerical data by grouping values into bins
- • Density histogram: height = relative frequency / bin width — area sums to 1, comparable to PDFs
- • Binning methods: Sturges, Scott, Freedman-Diaconis, Rice, Square Root — each has trade-offs
- • Normal overlay N(μ, σ) helps assess whether data is approximately normal
- • Skewness > 0.5: right-skewed; < -0.5: left-skewed; near 0: symmetric
Did You Know?
Expert Tips
Normal Data
Use Scott's rule. Density + normal overlay to check normality.
Skewed or Outliers
Use Freedman-Diaconis. IQR is robust.
Too Many Bins
Jagged, noisy histogram. Try fewer bins or a different method.
Too Few Bins
Oversmoothed, hides bimodality. Try Rice or Square Root for more bins.
Binning Methods Comparison
| Method | Formula | Best For |
|---|---|---|
| Sturges' | k = ⌈1 + log₂(n)⌉ | Classic, small n |
| Scott's | width = 3.49σn⁻¹/³ | Normal data |
| Freedman-Diaconis | width = 2×IQR×n⁻¹/³ | Skewed, outliers |
| Rice | k = ⌈2n¹/³⌉ | More bins |
| Square Root | k = ⌈√n⌉ | Simple heuristic |
Frequently Asked Questions
What is a density histogram?
Height = relative frequency / bin width. Total area = 1, so you can overlay probability density functions (e.g., normal) for comparison.
When should I use Scott's vs Freedman-Diaconis?
Scott's for normal/symmetric data. Freedman-Diaconis for skewed data or when outliers are present (uses IQR).
What does skewness mean?
Skewness > 0: right tail longer (e.g., income). Skewness < 0: left tail longer. Near 0: symmetric.
How do I interpret the normal overlay?
If the histogram bars roughly follow the red normal curve, the data may be approximately normal. Large deviations suggest non-normality.
What is kurtosis?
Measures tail heaviness. Excess kurtosis > 0: heavier tails than normal. < 0: lighter tails.
Can I use custom bin count?
Yes. Select Custom and enter your desired number of bins. The calculator will compute equal-width bins.
Binning Rules at a Glance
Official Data Sources
Disclaimer: This calculator provides histograms for educational and exploratory data analysis. The best bin width depends on your data and purpose. For publication, consider trying multiple methods and reporting the one that best represents your data.
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