How to enter a five-number summary
Each row is a group: a region, a class, a machine, a week. You type five numbers in order of size: minimum, lower quartile, median, upper quartile, and maximum. If you type them out of order, the chart sorts that row before it draws, so a swapped pair does not paint a box upside down. It is still better to enter them in order, because the fields are labeled in that order and a sorted surprise is harder to check.
The median is not the average. A group can have a high average and a low median when a few large values pull the average up. The box plot will not show the average. If the average is the number you need, put it in a table. The box shows where the middle half sits. A tall box means that middle half is spread out. A short box means the middle half is tight. A whisker that is much longer on one side means the outer values stretch that way.
This chart does not mark separate outlier dots. The whisker ends at the minimum and maximum you typed. If you already removed outliers by some rule, the whiskers are the ends you chose, and the subtitle should say so. If the minimum is a single strange value you do not want in the picture, do not type it as the minimum. Decide the rule before you draw, and use the same rule for every group. Comparing one group’s full range with another group’s trimmed range is not a comparison.
The vertical axis should cover every whisker. Leave the minimum and maximum blank unless you are aligning several charts. Title the axis with the unit: days, points, millimeters. Category names sit under the boxes. Keep them short. Color distinguishes the box from the whisker. The median is a dark line so it survives when the fill is light. Grid lines help a reader see that one median sits above another group’s entire box, which is often the sentence the chart exists to support.
Export PDF for a lab report, PNG for a slide, and JPEG when needed. If you want the shape of every measurement, paste the raw list into the histogram. If you want each pair of measurements, use the scatter plot. If you want the actual figures a reader must copy, use the table maker. The five numbers stay in this browser. Reset brings back the sample delivery times. Change them before you treat the picture as yours.