The smallest slice matters more than the count
What makes a pie chart hard to read is less the number of slices than how narrow the smallest one is. Even with four slices, a share of one percent spans only 3.6 degrees, which is far too narrow to hold a label inside the wedge. This tool converts each share you enter into a real angle, then checks the smallest slice and the total together.
How it is calculated
The angle is the share divided by 100 and multiplied by 360. The smallest angle that can carry a label depends on the typeface, the chart diameter and the label length, so no official value exists and the tool judges only against the threshold you enter. The sum and the angles are compared on the same 2-decimal values shown on screen, so the figures and the conclusion never point in opposite directions. Written as of October 2026.
Limits
No maximum slice count is given, because none is established and it depends on the case. The tool does not work out whether a label physically fits at your diameter and type size, what order the slices should take, or the inner radius of a donut chart.
Frequently asked questions
There is no accepted upper limit, because it depends on how the shares are distributed, on the chart diameter and on the label lengths. The tool offers no maximum; it computes each slice as a real angle and compares it with the threshold you set.
Below 100 the circle is left with a gap, above 100 the slices overlap. Rounding often leaves a total of 99.9 or 100.1, so check whether your charting library normalizes the values. This tool judges the sum rounded to 2 decimals.
You can pull the labels out on leader lines, or group the small shares into a single slice shown separately. Which of those is right depends on the data, and the tool does not decide for you.