Waterfall encodes values as signed bar height from a running total. Popularised in 1980s–90s consulting decks (McKinsey waterfall).
In reports, ads and assignments it fits P&L bridges, budget vs actual, headcount walks. Skip it when the story is a trend over many periods, not a bridge.
Principles
- Encoding — Waterfall encodes signed bar height from a running total.
- History — Popularised in 1980s–90s consulting decks (McKinsey waterfall)
- Fit — P&L bridges, budget vs actual, headcount walks
- Shared baseline — The eye compares length and position more accurately than area.
- Audience — PowerPoint, Excel or Google Sheets and Meta, Google and retail print share the same geometry.
Misconceptions
- Pretty equals true — Decoration rarely persuades; it slows reading.
- 3-D helps — Perspective distortion wrecks comparison. Keep it flat.
- More series is richer — Do not stack stories. One Waterfall, one claim.
- Default palette is fine — Rainbow defaults fail color-blind viewers and grey print. Change Excel or Google Sheets defaults.
Why it matters
- Work — Work: P&L bridges, budget vs actual, headcount walks. Readable in four minutes in PowerPoint.
- Ads — Ads: one number and one shape speak first in Meta, Google and retail print.
- School — School: for lab reports and poster boards, pick the form that answers the rubric.
- Craft — Craft: honour signed bar height from a running total and decoration falls away.
Waterfall: honour signed bar height from a running total, and switch when the story is a trend over many periods, not a bridge.