piechart

EvidenceCanvasSeries

Pie or donut chart with legend — proportional wedges.

Variant

Use for part-to-whole breakdowns with three to six slices. Add the donut modifier for a hole in the middle — visually cleaner for executive decks.

donutproportionpercentage

When to use

Three to six parts of a whole. Time allocation, budget breakdown, mix-of-business. Past six slices the wedges become unreadable and the legend overwhelms — split or pick the top five plus an Other slice.
Proportions matter more than precision. Pie charts are good at 'roughly a third', bad at 'is it 28% or 31%?'. If exact differences are the argument, reach for a bar chart (progress) where the eye can compare lengths directly.
Donut for executive decks. The donut modifier hollows the centre — cleaner, less crowded, and the hole reads as composed rather than as a missing slice. Default to donut for board / investor decks; reserve solid pies for analyst working sessions.

When not to use

Slices that don't sum to a whole. A pie of unrelated metrics is meaningless — the visual implies parts of a whole. If your values are independent measures, use stats or a bar chart instead.
Two slices. A two-slice pie is just a percentage with extra steps. Use big-number or split-panel metric — the audience can read '38% / 62%' faster than they can decode a half-and-half disc.
Comparing two pies. Side-by-side pies force the audience to compare wedge angles across two figures — humans are bad at this. Use grouped bars or a slope chart to land the comparison cleanly.

Authoring

<!-- _class: piechart donut -->

`Eyebrow · context`

## What the breakdown shows.

- First slice `40%`
- Second slice `30%`
- Third slice `20%`
- Fourth slice `10%`

Slots

Slot	Selector	Required	Description
`title`	`h2`	yes	Slide heading framing the breakdown.
`slices`	`ul > li`	yes	One li per slice: label text then a trailing inline-code value pill, e.g. - Marketing `40%` (slices are drawn proportionally to the values).
`detail`	`li > ul`	no	Optional nested sublist under a slice. Drives two surfaces from one source via the shared chart-family detail substrate (identical to funnel/map/quadrant/radar): (1) Present/Practice — the kernel keeps the label/value as-is, tags each wedge `<path>` with `data-mark`, and emits the sublist as an inert `<template class="chart-detail">` (inside a `.chart-details` wrapper) the reveal layer reads; (2) the static PDF — the same detail is folded into the slide's speaker note (`Label (value): item · item`) as a Marp-faithful comment, which notes-core lifts into the per-slide note channel (a PDF text annotation + the hidden `aside`). The note rides the existing channel, so the chart pixels stay byte-identical. A pie with no sublists emits no note and is unchanged. Detail sublists must be bullet (`-`/`*`) lists, not numbered.

Anatomy

┌─────────────────────────────────────────┐
│  header                                 │
│          Distribution heading           │
│                                         │
│                  ╭──────╮               │
│                 │▓▓▓░░░░│               │
│             │▓▓░░░░░│  ◆ 40%            │
│             │░░░▓▓▓░│  ◇ 35%            │
│              ╰──────╯   ○ 25%           │
│  footer                           1/19  │
└─────────────────────────────────────────┘

Variants

`donut` — Donut — hollow centre

Hollows the pie into a donut. Visually cleaner for executive decks; the centre is left blank for a calmer read. Default pick for board and investor material.

<!-- _class: piechart donut -->

`H1 2026 · 1,840 person-hours`

## Where the engineering quarter actually went.

The toil-and-on-call slice is the one nobody put in the roadmap.

- Signal Intake build `46%`
- Scoring policy work `22%`
- Decision Log integration `18%`
- Explaining the framework to stakeholders `9%`
- Toil and on-call `5%`

Refreshed weekly · figures from the time-tracking export

`cover` — Cover — full-bleed with a caption band

The chart-family cover modifier: the donut + legend fill the slide and the title + a one-line takeaway reflow into a bottom caption band carrying the chart sheen. For a hero breakdown where the proportion IS the message. Chart-scoped — not an all-layout modifier.

<!-- _class: piechart cover -->

`H1 2026 · 1,840 person-hours`

## Where the planning quarter actually went.

- Deck production `46%`
- Meetings about meetings `22%`
- Realigning on priorities `18%`
- Stakeholder management `9%`
- Actually deciding `5%`

Nearly half went to producing decks; the deciding itself was the smallest slice.

progresscomparable parts but precise differences matter
statsthe values are independent metrics, not a partition
big-numberthe headline is one slice, not the breakdown
kpithe slices need status framing and targets