18.1 Chart Types and Selection

Why Chart Choice Is an FMVA Skill

Excel Data Visualization and Dashboards is core course 13 on CFI's 15-course 2026 list. PowerPoint & Pitchbooks is core 14 and was refreshed on 27 February 2026. Together they carry Presentation & Visuals, about 5% of the final — not a trivia sidecar. A modeling case that dumps a raw three-statement sheet, or a multiple-choice item that asks which chart belongs on a variance pack, is this chapter. Elective courses such as Communication and Presentation Skills for Finance Professionals (which replaced Presentation of Financial Information on 27 February 2026) can count toward the three-elective eligibility rule, but elective content is not tested. Stay on the two cores.

A chart is a sentence in picture form. The exam tests whether you pick the sentence that matches the question, not whether you can add 3-D bevels. CFI's dashboard course has you build two complete dashboards with clustered columns, line charts, stacked mix charts, waterfalls, area charts, and a football field. Those are the types to know by name, by use, and by trap.

This chapter uses two running files. Apex Housewares (Chapter 17) is the FP&A pack: FY2026 actual revenue $86.1 million versus a lock of $80.0 million. Alder Coatings (Chapters 15–16) is the valuation pack: Gordon year-end enterprise value $2,071 million, equity $1,301 million, $26.02 per diluted share.

Column and Bar Charts for Comparison

A column chart (vertical bars) or bar chart (horizontal bars) compares magnitudes across categories. Use columns when categories are few and the axis is time or a short label. Use bars when labels are long — region names, peer companies — so the type remains readable.

Apex's FY2026 bottom-up regional build versus the FY2025 run-rate that sat under the $80 million lock:

A clustered column with two series — budget analog and actual — answers who beat the lock in one glance. East, Central, and West all rose. A pie of 2026 actuals cannot show the beat, because a pie has no budget series.

Exam trap: a 3-D column. Depth adds no data and hides the West bar. CFI formatting drills 2-D charts, data labels, and display units ($ millions), not extrusion.

Line Charts for Time Series

A line chart shows change over a continuous time axis. Apex's annual revenue: FY2023 $72 million, FY2024 $76 million, FY2025 $80 million, FY2026 $86.1 million. Connecting those four points is the right picture of trend. Four isolated columns also work; the line is better when you want slope, and it is the default for monthly series (12–36 points).

Do not use a line for unordered categories (East / Central / West). Those are not a time sequence. A line between East and Central invents a path that does not exist.

Stacked Charts for Mix

A stacked column or stacked bar shows composition and total together. CFI's dashboard course explicitly builds a stacked revenue chart. Suppose Apex's $86.1 million splits:

Two stacked columns (2025, 2026) show the total rising $6.1 million and Premium's mix rising from 22.5% to 25.0%. That mix shift is why average selling price went from $40 to $41 in Chapter 17 — not necessarily a list-price increase.

100% stacked columns drop the total and show only mix. Use them when the question is mix, not dollars. Do not 100% stack a P&L waterfall; you would hide that revenue is $86.1 million.

Stacked area is CFI's expense-analysis tool on Dashboard 1. It is a mix-over-time chart. It is not a replacement for a variance waterfall.

Scatter Charts for Correlation

A scatter chart plots two numeric variables to show association, not time. Example: regional marketing spend versus regional revenue. East spent $1.8 million and printed $38.5 million; Central $1.2 million and $30.1 million; West $0.9 million and $17.5 million. The cloud is three points — too few to claim a law — but the chart type is still scatter, not a line.

Exam trap: drawing a line chart through those points and calling it causation. Scatter does not prove that another $0.1 million of ads would add a mechanical amount of sales. It shows whether the two series move together.

Waterfall Charts for Bridges

A waterfall (bridge chart) starts at a total, adds and subtracts signed steps, and lands on a new total. CFI's dashboard course builds a waterfall as a named lesson. Two FMVA-native uses:

1. Net-income (P&L) bridge for Apex FY2026 actuals (compact teaching P&L; SG&A actual $21.5 million, depreciation and amortization $3.0 million, interest $1.8 million, tax 25%):

The first and last columns are totals (connectors). The middle columns are floating decrements. That is a net-income waterfall.

2. Enterprise-value to equity bridge for Alder Coatings:

$1,301 million / 50.0 million diluted shares = $26.02. The waterfall is the equity bridge from Chapter 15 in chart form. A clustered column of those six signed items without a running total is not a bridge; it is a bar chart of ingredients.

Variance waterfalls (Chapter 17) are the third native use: +$4.0 million volume, +$2.1 million price, −$2.4 million COGS quantity, −$1.05 million COGS rate = +$2.65 million gross-profit variance.

Combo Charts for Actual Versus Budget

A combo chart overlays two chart types on one plot, usually columns plus a line. The CFI-native use is actual versus budget as clustered columns and a margin or growth percent as a line — or two column series (actual, budget) without a second axis at all.

Apex revenue: budget $80.0 million column, actual $86.1 million column, and a line for gross margin 40.0% budget versus 40.2% actual ($34.65 / $86.1). The columns answer the dollar question; the line answers the quality question. You do not need a second axis if you plot the margin as a separate small chart. If you do combine them, read the dual-axis warning next.

Avoid Pie Charts for More Than Three or Four Slices

A pie chart encodes share of a single total as angles. Humans compare angles poorly once the slice count rises. CFI-aligned rule for the exam: do not use a pie for more than three or four slices. Three-product Apex mix (Core 60%, Premium 25%, Seasonal 15%) is the outer acceptable case. Twelve SG&A cost centers is a pie of junk. Use a sorted bar for those twelve lines: the longest bar is the largest cost, and the axis still has dollars.

Pies also fail comparison across years. Two pies (2025 and 2026) force the reader to jump between images to see that Premium rose from 22.5% to 25.0%. Two stacked columns keep the total and the mix on one axis.

Donut charts are pies with a hole. Same slice-count rule. 3-D pies are never acceptable: they distort angle into perspective.

Dual-Axis Traps

A dual-axis (secondary axis) chart plots two series against independent scales. The trap is that the series look like they share a zero and a slope when they do not.

Worked distortion: Apex revenue $80.0 → $86.1 million (left axis scaled $78 to $88) and a quality metric that moved from 20.0% to 20.4% (right axis scaled 19.8% to 20.6%). Both lines shoot up the plot. The revenue beat is real (+7.6%). The 40-basis-point mix move is small. The chart lies by scale.

Worse: putting revenue in $ millions and WACC in percent on one dual-axis plot. Alder's $2,071 million enterprise value and 9.0% WACC do not belong on the same picture. They are not a time series together; they are an input and an output.

Exam-safe dual axis: same-context series that would otherwise be unreadable (units in thousands on the left and average selling price in dollars on the right), with both axes labeled, zero shown or disclosed, and a title that states the two scales. When in doubt, two charts.

CFI combo lessons (actual versus budget, growth-rate data on a stacked revenue chart) are not a license to dual-axis every dashboard. A combo chart can use a single axis when both series are dollars. The second axis is the exception, not the professional default.

Direct Labels Beat Legends

A legend off to the side forces the eye to decode color, then return to the bar. Direct labels — data labels on the series, or the series name at the end of the line — keep the number on the mark. CFI's dashboard course has an explicit lesson on adding totals with data labels. For a three-region clustered column, put 38.5 on the East actual bar. You may still keep a small legend if you have two series (Budget / Actual), but the values should sit on the columns.

Display units: if the model is in $ thousands, the chart axis must say $ thousands. Alder is in $ millions. Writing $2,071 with no unit, or $2,071,000,000 on a pitchbook, is an integrity miss (section 18.4).

Chart-Selection Map

Pick the chart that answers one question. Section 18.2 turns that rule into a dashboard.

Exam traps on chart types

• A pie of twelve cost centers, or two pies to compare years.
• A 3-D column that hides the smallest region.
• A line chart through East–Central–West as if they were time.
• A dual-axis of dollars and WACC, or of dollars and a 40-basis-point margin tick drawn full height.
• Calling a clustered column of bridge ingredients a waterfall because the title says Bridge.
• Leaving the legend as the only decoder and omitting $ millions on the axis.