Pie Chart: How to Make It Online and Add It to Your Paper (APA7)
A pie chart splits a circle into slices whose sizes show each category's share of the whole.
What is Pie Chart?
A pie chart splits a circle into slices whose sizes show each category's share of the whole.
When to use it
Use it only when you have a few categories (about two to five) that add up to a meaningful 100%, for example the share of participants by transport mode. For comparisons across many categories or groups, a bar plot is easier to read.
Example question: What share of respondents commutes by each mode of transport?
Preparing your data
One row per participant and one column with the category label, or two columns: the category and its count.
Example dataset (simulated; first rows of 200): id, commute_mode (Car, Bus, Bicycle, Walking).
| id | commute_mode |
|---|---|
| 1 | Bus |
| 2 | Bicycle |
| 3 | Walking |
| 4 | Car |
| 5 | Car |
| 6 | Walking |
Download the full example CSV to practise. If the tool asks for a different layout, follow the instructions on its page.
How to run it on StatFas
- Open the Pie Chart tool. You do not need an account to run an analysis.
- Enter your data or upload your file, laid out as described in Preparing your data.
- Select your variables. Choose the categorical variable. If your data are already counted, choose the category column and the count column.
- Choose any options the tool offers (for example the confidence level, a post hoc test or the error bar type) and run the analysis.
- Read the results on the page. Check the assumptions first, then the test statistic, the p-value and the effect size.
- To save your results, log in or create a free account. Every analysis stays free; the account is only needed to download.
Assumptions and checks
- Slices must be mutually exclusive and sum to the whole.
- Keep the number of slices small; merge rare categories into "Other".
- Label each slice with its percentage, because angles are hard to compare by eye.
- Order the slices from largest to smallest, starting at 12 o'clock.
Key numbers to look at
- Slice size: the percentage of cases in each category.
- Labels with category name and percentage.
- Total N, which should appear in the caption.
Effect size
A chart does not have an effect size. Use a chi-squared test or binomial test to test whether the shares differ from expectation.
Benchmarks such as small, medium and large are conventions (Cohen, 1988), not rules. Interpret size in the context of your field.
Reporting Pie Chart in APA7 style
Template
Share of Respondents by Commute Mode
[figure]
Note. N = XXX. Percentages may not sum to 100 because of rounding.
Worked example (simulated data)
The numbers below were computed from the example CSV above, so you can reproduce them. They illustrate the format and are not real findings.
| Commute mode | n | % (slice size) |
|---|---|---|
| Car | 88 | 44.0 |
| Bus | 61 | 30.5 |
| Bicycle | 27 | 13.5 |
| Walking | 24 | 12.0 |
Figure caption (APA7 style)
Figure 1
Share of Respondents by Commute Mode
Note. N = 200. Percentages may not sum to 100 because of rounding.
APA7 reminders: italicise statistical symbols (M, SD, t, F, p, r), report exact p-values to two or three decimals (use p < .001 for very small values), omit the leading zero for values that cannot exceed 1 (.45, not 0.45), and put degrees of freedom in parentheses. See the APA7 cheat sheet.
Common mistakes
- Using a pie chart for more than about six categories.
- Showing a pie chart for data that do not sum to a whole (for example several answers per person).
- Using 3-D effects, which distort the slice sizes.
Related analyses and alternatives
- Bar Plot: A clearer chart for comparing category sizes.
- Frequency Analysis: For the exact counts and percentages.
- Chi-squared Test: To test whether the shares differ from expected.
Not sure which analysis you need? Use the test chooser.
Frequently asked questions
Is a pie chart acceptable in APA style?
Yes, but APA guidance favours the simplest figure that communicates the result, and bars are usually easier to compare. Use a pie chart for a few categories and a clear part-to-whole message.
Why do my percentages add to 99.9% or 100.1%?
That is rounding. Add a note that percentages may not sum to 100 because of rounding.
References
American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.). https://doi.org/10.1037/0000165-000
This guide is for learning and for preparing results for your own reports. You remain responsible for choosing an appropriate analysis, checking its assumptions and interpreting the results. Follow the formatting rules of your journal or institution where they differ from APA7.