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.
Parts
- Mark — The core mark of Waterfall is signed bar height from a running total.
- Scale — The scale must show zero (or a declared break) and units.
- Axis — Axis titles name the variable, not a mood.
- Legend — A legend is weaker than a direct label. Write beside the mark when you can.
- Label — Numbers are optional. If comparison is the job, label the ends only.
- Grid — Keep the grid faint. Data should own the ink.
- Annotation — One annotation sentence. Date the source.
- Frame — A thin frame. Never a 3-D box.
Variants
- Bridge chart — Variant 1 of Waterfall. Same encoding, different layout.
- McKinsey cascade — Variant 2 of Waterfall. Same encoding, different layout.
- Delta bars — Variant 3 of Waterfall. Same encoding, different layout.
- Waterfall 4 — Variant 4 of Waterfall. Same encoding, different layout.
Labels
- Axis — On Waterfall, make Mark readable.
- Legend — On Waterfall, make Scale readable.
- Label — On Waterfall, make Axis readable.
- Grid — On Waterfall, make Legend readable.
- Annotation — On Waterfall, make Label readable.
Waterfall: honour signed bar height from a running total, and switch when the story is a trend over many periods, not a bridge.