This entry is part of the Chart Index, the reference library for the Chart Design Field Guide.

The funnel chart is the bar chart's narrative cousin. A sequence of horizontal bars, each narrower than the one above, visualises a linear process where volume decreases at each step. Conversion funnels (visitors → leads → customers), recruitment pipelines (applications → interviews → offers → hires), and sales pipelines all reach for the form because it makes the attrition story visual.

The form's controversy is that it adds shape (the tapering wedge) on top of length (the bar). Tufte would call the wedge chartjunk; Few would call it acceptable when the metaphor matches the data. The bar lengths carry the data; the wedge is decoration that reinforces the funnel concept. Whether that decoration is worth it depends on the audience and the context.

What it is

A funnel chart maps a sequence of process stages to vertical position and a quantitative variable (count, percentage, or absolute value) to the width of a centred horizontal bar at each stage. The bars taper from a wide top (highest stage volume) to a narrow bottom (lowest stage volume), producing a visual wedge or funnel shape. The visual emphasises drop-off between stages.

The hero chart above follows 24,000 sessions through five stages to 1,008 purchases. Each part's width is the count at that stage, printed inside it, and the blended sides between parts draw the drop-off as a slope: the steepest fall is between product view and add-to-cart, where two thirds of the remaining sessions leave. The single hue darkens towards the top so the widest stage is also the heaviest. Randomise the counts and the wedge re-shapes; hover a part for its share of the top stage.

When to use it

Funnel charts are the right choice when:

  • The data is a linear, monotonically-decreasing process — every step has fewer subjects than the previous.
  • The reader's question is "where in the process are we losing people, and by how much?"
  • You have 3–7 stages. Fewer is just a bar chart; more loses the funnel shape's clarity.
  • The audience expects the form — marketing, recruiting, sales operations.
  • The drop-off pattern is non-trivial and worth examining stage-by-stage.

When not to use it

  • Non-monotonic processes. If stages can grow or shrink in any order (a user journey with branching), use a Sankey.
  • Many parallel funnels. Side-by-side funnels become hard to compare. Use stacked bars or a small-multiples bar chart.
  • Single-stage drop-off. A two-stage funnel is just a percentage. Use a paired number or a simple bar.
  • When precision is the point. Funnels emphasise narrative; tables and bar charts emphasise precision.

Design principles

Show absolute values and drop-off rates

Each stage should display both the absolute count (5,280 added to cart) and the percentage from the previous stage (34 % of product views). The absolute carries the magnitude; the rate carries the attrition story. Print the count inside the part; put the rates in the caption or as a small annotation beside each boundary.

Compare the funnel with the bar it replaces

The funnel's tapering shape requires centred parts (parts get narrower symmetrically). Left-aligned bars are not funnels; they are descending horizontal bars — and they are also the more precise chart, because every bar starts at the same baseline. The pair below shows the same five stages both ways. Choose the funnel when the audience wants the story; choose the bar when they want to measure.

As horizontal bars: the bare data
Five stages on a common baseline. The reader can measure any two stages against each other, and the value axis says exactly how many sessions each bar represents. There is no wedge, and no story beyond the numbers.
As a funnel: the wedge as narrative
The same five counts, centred and blended. The chart now reads as a single object narrowing from top to bottom, and the drop between product view and add-to-cart is the visual event of the figure. The widths are still proportional; only the framing has changed.

Use a single hue

Funnel stages share an axis of meaning. A single accent colour throughout, stepped in lightness so the widest stage is the darkest, suffices. Multi-coloured stages compete with each other and add no information: the stages are not categories, they are one population shrinking.

A colour per stage: five things competing
Each stage in a different hue from the categorical palette. The eye is drawn to the orange and the red before it has read the shape, and it starts looking for what the colours mean. They mean nothing.
One hue in lightness steps: one population
The same funnel in a single blue, darkest at the top. The stages read as one thing getting smaller, and colour has been kept in reserve for the day a second funnel needs to be told apart from this one.

Annotate the drop-off rates between stages

Between each pair of stages, show the conversion rate as a small annotation: 34 % beside the boundary, or in the caption. Cumulative conversion (from top: 4.2 %) helps contextualise the journey. The dashed separators between parts are the natural anchor for these numbers.

Show the conversion rate prominently

The headline number — 4.2 % end-to-end conversion — deserves a prominent placement, often in the subtitle or as an annotation at the bottom of the funnel.

Compare funnels side-by-side, not overlaid

For A/B testing or cohort comparison, place two funnels side by side, or one above the other, drawn to the same scale. Overlaying creates visual confusion; comparison through paired panels is clearer. The two funnels below share their top stage so the widths are directly comparable, and the difference in the lower stages is the whole result of the test.

Variant A: the existing four-step checkout
Control. 12,000 sessions, 504 purchases — a 4.2 % end-to-end conversion, with the largest loss between product view and add-to-cart.
Variant B: express pay in the cart
Treatment, same number of sessions. The upper funnel is unchanged; the lower funnel is visibly fatter, because fewer carts are abandoned at checkout. 5.9 % end-to-end. Same scale, same stages, so the eye reads the difference as width.

Resist 3D funnels

The most common funnel chart pathology in dashboard tools is the 3D perspective funnel — a cone seen from an angle. It distorts every encoding and adds nothing. The form is already at risk of being decorative; do not make it more so.

Anatomy

The composition of a funnel chart
An anatomical guide

A funnel chart's anatomy is centred horizontal parts whose widths decrease through the stages, with each stage labelled with its volume and the inter-stage drop-off. The form is narrative-led; the precision lives in the labels.

  • Sankey diagram — for flows with branches, merges, or non-linear paths.
  • Horizontal bar chart — the unvarnished version of the funnel.
  • Pyramid chart — same form, used for demographic age distributions.
  • Cohort retention curve — for the same drop-off question over time rather than stages.
  • Bullet chart — for a single stage's actual-vs-target performance.

Reading list

  • Few, S. (2006). Information Dashboard Design. On funnels, gauges and the other dashboard forms that trade precision for metaphor.
  • Knaflic, C. (2015). Storytelling with Data. Funnels as narrative reinforcement.
  • Tufte, E. (2001). The Visual Display of Quantitative Information. On chartjunk and the data-ink ratio.