Pie Chart Maker

How to Use the Pie Chart Maker

1. 1. Enter the parts. One slice per line: a label, a comma and a value — Walk, 42. Counts work as well as percentages; the tool divides each value by the total to get its share. A trailing % sign is fine.
2. 2. Choose pie or donut, and the labels. A donut prints the total in its center. The slices can show percentages, values, both, or nothing; a label that does not fit inside its slice moves just outside the rim.
3. 3. Tidy the slices. Order them largest first unless the categories have an order of their own, such as a rating scale. Tick Combine small slices to merge every slice under a threshold — 5% to start with — into one gray “Other” slice. If your values are percentages, tick My values are percentages of one whole to check that they add up to 100.
4. 4. Title and export. Add a title, switch on APA style if the chart is going in a paper, and download the SVG or PNG.

How the Slices Are Calculated

Each slice's share is its value divided by the total, and its angle is that share of 360°. In the example, 42 of 100 surveyed students walk to campus, so the Walk slice is 42% of the circle: 0.42 × 360° = 151.2°. Slices start at 12 o'clock and run clockwise, the order most readers expect.

When a Pie Chart Works — and When a Bar Graph Is Better

A pie chart answers one question well: how does a single whole divide into a few parts? It works when the parts add up to something meaningful — all respondents, a whole budget — when there are only a few of them, two to six, and when one or two shares are large enough to matter.

• Use a bar graph to compare the parts with each other. People judge angles and areas less accurately than lengths on a common baseline, so slices of 23% and 27% look almost the same while bars of 23 and 27 do not. The Bar Graph Maker takes the same data.
• Use a bar graph when there are more than six or seven categories, or when you need to compare two wholes — this year and last, two groups. Side-by-side pies force readers to match colors and compare angles between circles.
• Use a bar graph when the values are not parts of a whole: averages, rates, scores, or answers to a question that allowed several choices.
• Use a sentence when there are only two parts. “62% of respondents agreed” is clearer than a two-slice pie.

Parts of a Whole: The Check That Matters

Pie slices must be mutually exclusive and together make up the whole. A question that allows more than one answer breaks this: if 70% of students use the library and 60% use a café, the percentages add up to 130%, and no pie can show them honestly. The tool warns when values marked as percentages do not add up to 100%, leaves out zero and negative values (and says which), and lists exactly which categories went into “Other”.

Rounding can make honest percentages sum to 99% or 101%. The tool computes every share from your raw values, so the shares add up to exactly 100% before their labels are rounded to one decimal. If you type rounded percentages yourself, a total within half a point of 100 passes the check.

APA Style and Common Mistakes

For an APA 7 paper, switch on APA style figure: the title leaves the image, and the figure number (bold) and title (italic title case) are shown above the chart for you to copy into the paper. The legend stays inside the image, as APA asks. Add a note under the figure giving the total, such as Note. N = 100 respondents.

• 3-D pies. Tilting the circle makes the front slices look bigger than back slices of the same size.
• Exploded slices. Pulling a slice out of the circle breaks the outline readers use to judge its angle.
• Too many slices. This tool gives eight slices their own colors and merges the smallest of the rest into “Other” rather than repeating a color.
• No numbers. Angles are hard to read precisely, so print the percentages on the slices or give them in a table.

Frequently Asked Questions

How do I make a pie chart with percentages?

Enter each category with its count or percentage, one per line, and keep Labels on the slices set to Percentages. The tool divides each value by the total, so counts such as 42, 31, 18 and 9 become 42%, 31%, 18% and 9%. Choose Values and percentages to show both.

How do I calculate the angle of a pie chart slice?

Divide the slice's value by the total to get its share, then multiply by 360°. A category with 18 of 100 responses has a share of 0.18, so its angle is 0.18 × 360° = 64.8°. Percentages work the same way: 25% is a quarter of the circle, 90°.

What should I do with very small slices?

Combine them. Tick Combine small slices into “Other” and set the threshold; every slice smaller than that share joins one gray “Other” slice, and the tool lists which categories it holds so you can explain them in a note. It only combines when at least two slices qualify, since an “Other” of one category just hides its name.

Why don't my percentages add up to 100%?

Usually for one of two reasons. Rounding each share can leave a total of 99% or 101%, which is harmless. A total well above 100% means the categories overlap — respondents could choose more than one answer — and then the data are not parts of one whole and belong in a bar graph instead.

Should I use a pie chart or a bar graph?

Use a pie chart only to show how one whole splits into a few parts, when the rough proportions are the message. Use a bar graph for everything else — comparing parts with each other, many categories, several groups, or values that are not shares of a total — because lengths are easier to compare than angles.

What is a donut chart?

It is a pie chart with the center cut out, which leaves room to print the total in the middle. Readers judge the slices by their arcs rather than their angles — no more accurately — so the same advice applies: keep to a few slices and label them.