Reading Pie Charts

Pie charts appear in roughly 1 out of 9 QR data sets. They show how a total is divided into parts, with each slice representing a proportion. Pie chart questions typically require you to calculate absolute values from percentages, compare slices, or work backwards from a known value to find the total.

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How Pie Charts Present Data

A pie chart represents a whole (100%) divided into segments (slices). Each segment's size is proportional to the quantity it represents.

Pie charts in QR may show:

• Percentage labels on each segment (e.g., 25%, 15%, 35%, 25%)
• Degree labels (e.g., 90°, 54°, 126°, 90° — adding to 360°)
• Value labels (e.g., £2,500, £1,500, £3,500, £2,500)
• No labels — requiring you to estimate segment sizes

The total is usually given separately — either in the title, a caption, or the question itself.

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Converting Between Degrees, Percentages, and Values

Degrees to Percentage

Since a full circle is 360°:

Percentage = (Degrees ÷ 360) × 100