The Histogram

A one-page histogram — the chart that takes a heap of raw readings and shows you their shape. Paste a column of numbers — response times, test scores, order values, ages, delays — and the tool sorts them into evenly-spaced ranges along a number line and counts how many land in each, then draws a bar for every range as tall as its count. Where the numbers pile up the bars stand tall; where they thin out the bars shrink; and the silhouette across the top tells you at a glance whether the data is bunched or spread, symmetric or lopsided, single-peaked or split in two. It picks a tidy round bin width for you — 1, 2, 5, 10 and the like — so the axis edges stay legible, or you can ask for a rough number of bins and it fits the nearest clean width. The mean is drawn as a solid line and the median as a dashed one, laid straight over the bars, so you can see how the average sits inside the spread and how far a long tail has dragged it off the middle. Unlike a bar chart, whose bars are separate labelled categories with gaps between them, a histogram's bars touch, because the axis underneath is one continuous number line cut into slices — which is exactly why it is the natural partner to a box plot: the box plot boils a distribution down to five numbers, the histogram shows its whole outline. Paste your numbers in any layout — a column, a row, comma- or space-separated — and they sort, bin and count themselves; leave it blank to print an empty frame and tally by hand.

• Landscape
• 1 page
• Tracking

Best for: Seeing the shape of a pile of raw numbers — where they cluster, how they spread, whether they lean — as a row of touching bars over a number line, with the mean and median drawn on top. Response times, test scores, order values, ages, delays.