Examples · Histogram

Histogram examples

A histogram takes a pile of raw measurements, sorts them into equal-width bins, and draws one column per bin — the shape that appears is the distribution. Under the hood each histogram example here is a column chart whose categories are numeric ranges; the histogram maker does the binning for you.

When to use it

  • Understanding how measurements distribute: response times, scores, ages, durations
  • Spotting skew, gaps and second peaks that an average hides
  • Summarizing hundreds of raw readings into one readable shape

Not the right shape?

Comparing named categories — a histogram's x-axis is a continuous scale chopped into ranges, not a set of labels. That's a bar chart's job.

Real-world examples

Exam scores, skewed left

Most of the class clears 70 and a thin tail doesn't — the skew is the finding, and no single number would have shown it.

Open in maker with this data

View the spec 
{
  "type": "column",
  "theme": "mint",
  "title": "Final exam scores, 84 students",
  "source": "One course, spring term",
  "data": {
    "labels": [
      "40–50",
      "50–60",
      "60–70",
      "70–80",
      "80–90",
      "90–100"
    ],
    "series": [
      {
        "name": "Students",
        "values": [
          3,
          6,
          12,
          27,
          24,
          12
        ]
      }
    ]
  }
}

API response times, long tail

The classic latency shape: a tall peak of fast responses and a tail that never quite reaches zero. The tail is what your slowest users feel.

Open in maker with this data

View the spec 
{
  "type": "column",
  "theme": "ink",
  "title": "API response times (ms)",
  "source": "24h of production traffic, sampled",
  "data": {
    "labels": [
      "0–100",
      "100–200",
      "200–300",
      "300–400",
      "400–500",
      "500+"
    ],
    "series": [
      {
        "name": "Requests",
        "values": [
          412,
          268,
          96,
          41,
          18,
          11
        ]
      }
    ]
  }
}
Open this chart in a maker Histogram maker from scratch

Questions people ask

What does a histogram show?

The distribution of one numeric variable: where values concentrate, how far they spread, whether the shape is symmetric or skewed. Each column counts how many readings fell into that range.

Histogram vs bar chart — aren't they the same?

They look alike and differ in meaning. A bar chart compares separate categories that could be reordered freely; a histogram's bins are consecutive slices of one numeric scale, so their order is fixed and their widths are equal. Sorting a histogram's columns would destroy it.

How many bins should I use?

The histogram maker starts with Sturges' rule (roughly log₂ of the count, plus one) and lets you override it. Too few bins blur the shape; too many turn it into noise — nudge the count until the story stabilizes.