The Donut Chart

A one-page donut chart that takes one whole — a budget, a day, a portfolio, a project's effort — and splits it into wedges, each drawn to its share of the total and laid clockwise from twelve o'clock, so the biggest part is the first thing your eye meets. It answers the question a column of numbers makes you work out in your head: what actually dominates, and by how much. In donut style the hole in the middle holds the running total, so you read the parts against the sum without any arithmetic; in pie style the wedges meet at the centre for the plainest possible picture. Because the whole point is proportion, every wedge carries its share as a percentage right on it when it is wide enough, and a legend down the right names each colour with its exact value and share so even a thin sliver stays readable — the largest part is called out at the top. It works best with a handful of parts, from two to eight, where each is a clean piece of a single whole; when there are many small pieces a treemap or a bar reads better, but for a few big shares nothing beats the circle. Use it for a monthly budget by category, where your day's twenty-four hours go, an investment portfolio by holding, revenue by product line, website traffic by source, a vote or survey split by option, or storage by folder — any whole you want to break into a few proportional parts. List a label and a value per line and the wedges size, colour, order and label themselves; leave it blank to print a guide ring and shade it in by hand.

• Landscape
• 1 page
• Tracking

Best for: Breaking one whole into a few proportional parts and seeing what dominates — a budget by category, a day's hours, a portfolio by holding — as colour-coded wedges, donut or pie, each carrying its share.