Area Charts: The Complete Guide to Visualizing Trends and Composition

Q: How many data points should an area chart have?

Area charts work best with 7-50 data points on the x-axis. Fewer than 7 and the trend isn't meaningful. More than 50 and the chart may need aggregation (weekly instead of daily, quarterly instead of monthly). For very long time series, see our time series guide.

Q: Should I use a stacked area chart or multiple line charts?

Stacked area if the total matters and you have 3-5 series. Multiple line charts (small multiples) if you need to compare individual trends precisely or have 6+ series. The stacked format emphasizes the whole; separate charts emphasize parts.

You need to show how values change over time. A line chart works, but you also want to convey the magnitude of those values. The answer? An area chart.

Area charts sit in a sweet spot between line charts and bar charts. They show trends like a line chart, but the filled region underneath gives viewers an intuitive sense of volume and scale. When stacked, they reveal how different parts contribute to a whole over time.

Yet area charts are one of the most misused chart types. Use them wrong and you get an unreadable mess of overlapping colors. Use them right and you get one of the clearest ways to communicate growth, composition, and cumulative trends.

In this guide, you'll learn exactly when to use area charts, how to avoid the common mistakes, and how to create effective ones in minutes.

What Is an Area Chart?

An area chart is a line chart with the region between the line and the x-axis filled with color. That fill does more than look pretty. It emphasizes the magnitude of values, making it easy to see how much something has grown or shrunk over time.

The concept was popularized by William Playfair, the Scottish engineer who invented many of the chart types we use today. His 1786 Commercial and Political Atlas included some of the earliest area charts, visualizing England's trade balance over decades.

There are three main variations:

Simple area chart: One data series with a filled region. Shows the trend and magnitude of a single metric.
Stacked area chart: Multiple series stacked on top of each other. Shows how parts contribute to a total over time.
100% stacked area chart: Like a stacked area chart, but normalized to show percentages. Each vertical slice sums to 100%.

When to Use an Area Chart

Area charts work best in specific scenarios. Here's when they shine and when you should pick something else.

Use an Area Chart When:

Showing volume over time. Revenue growth, website traffic, user signups. The filled area makes cumulative magnitude immediately visible.
Comparing parts of a whole over time. Stacked area charts are ideal for showing how market share, budget allocation, or traffic sources shift across periods.
Emphasizing the total. If the overall sum matters as much as individual trends, a stacked area chart shows both. A stacked bar chart does too, but area charts handle many time periods more gracefully.
Highlighting cumulative growth. When your story is about accumulation (total users, cumulative revenue, total downloads), the filled region reinforces the "growing pile" metaphor.

Don't Use an Area Chart When:

Comparing exact values between series. Overlapping filled regions make precise comparison difficult. Use a line chart or grouped bar chart instead.
You have more than 5-6 series. Stacked area charts become unreadable with too many layers. If you have many categories, consider a small multiples layout or aggregate into fewer groups.
Values frequently cross each other. When series overlap and interleave, area fills create visual confusion. A plain line chart handles crossovers much better.
Showing proportions at a single point in time. That's what pie charts, donut charts, or bar charts are for.

Area Chart vs Line Chart: When to Choose Which

This is the most common question. Both show trends over time. When should you add the fill?

Scenario	Use Area Chart	Use Line Chart
Showing magnitude/volume matters	Yes
Comparing 2-3 series precisely		Yes
Showing parts of a whole over time	Yes (stacked)
Many overlapping series (4+)		Yes
Highlighting cumulative growth	Yes
Detecting exact trend changes		Yes
Showing a single series with emphasis	Yes

Rule of thumb: If magnitude matters, use an area chart. If the shape of the trend matters more, use a line chart.

According to visualization researcher Stephen Few, the filled area adds visual weight that draws attention to the magnitude of values rather than just the rate of change. This makes area charts particularly effective for executive dashboards where the "how much" question is as important as the "what direction" question.

Stacked Area Charts: Showing Composition Over Time

Stacked area charts are where area charts truly differentiate themselves. No other chart type shows composition changes over time as intuitively.

How Stacked Area Charts Work

Each data series is stacked on top of the previous one. The bottom of each colored band represents the cumulative total of all series below it. The top line shows the total of all series combined.

This means you can read two things at once:

Individual trends: The height of each colored band shows how each category changes.
The total: The top edge shows the overall total over time.

Real-World Examples

Revenue by product line: A SaaS company with three products can show how total revenue grows while revealing which product drives that growth. If Product A's band is widening while Product B's shrinks, the story is immediately visible.

Traffic sources over time: Marketing teams often use stacked area charts to show organic, paid, social, and referral traffic. You see total traffic trending up while also spotting that organic is growing and paid is flat. Google Analytics uses this exact visualization in its traffic acquisition reports.

Energy consumption by source: Our World in Data uses stacked area charts extensively to show how the global energy mix (coal, oil, gas, nuclear, renewables) has shifted over decades. The chart simultaneously shows total energy consumption rising and the share of renewables increasing.

When to Use 100% Stacked Area Charts

Use the 100% variant when the proportion matters more than the absolute values. Each vertical slice sums to 100%, so you see how shares shift over time without being distracted by overall growth.

Example: Showing browser market share from 2010-2026. The total (100%) stays constant, but you see Chrome growing from a sliver to dominance while Internet Explorer vanishes.

Best Practices for Area Charts

1. Limit Your Series

Keep stacked area charts to 3-5 series maximum. More than that and the chart becomes an unreadable layer cake. If you have 10 categories, aggregate the smallest ones into an "Other" group.

2. Order Series Strategically

Place the most important or largest series at the bottom. Bottom series are easiest to read because they have a flat baseline (the x-axis). Upper series are harder to read because they sit on a wavy baseline. The D3.js visualization library documentation recommends this approach for all stacked visualizations.

3. Use Semi-Transparent Fills

For non-stacked area charts comparing multiple series, use transparency (opacity 0.3-0.5) so overlapping regions don't hide data. The lines should remain fully opaque for readability.

4. Always Include the Zero Baseline

Area charts encode data as the height of the filled region. If the y-axis doesn't start at zero, those heights are misleading. This is the same principle as with bar charts. See our guide on why your chart looks wrong for more on this.

5. Use Colorblind-Safe Palettes

With multiple stacked series, color is the only way to distinguish categories. Make sure your palette works for the 8% of males with color vision deficiency. Blue, orange, and teal are reliably distinguishable. Check our colorblind-friendly charts guide and use tools like ColorBrewer to pick safe palettes.

6. Add Direct Labels When Possible

Instead of relying only on a legend, label each area directly on the chart. Place labels in the widest part of each colored band. This reduces back-and-forth between the legend and the data, following Edward Tufte's principle of minimizing eye travel.

Common Mistakes with Area Charts

Mistake #1: Using Area Charts for Unrelated Series

A stacked area chart implies that the series add up to a meaningful total. If you stack "temperature" and "humidity," the combined height means nothing. Only stack series where the sum makes sense (revenue streams, traffic sources, population segments).

Mistake #2: Too Many Categories

More than 5-6 stacked layers makes the chart unreadable. The middle layers sit on wavy baselines, making it impossible to judge their individual trends. Solution: combine small categories into "Other," or use separate line charts (small multiples) for each series.

Mistake #3: Ignoring Overlap in Non-Stacked Charts

When two non-stacked area series overlap, the one on top hides the one behind it. Always use transparency, or consider switching to a line chart. Overlapping opaque areas are one of the most common visualization mistakes in dashboards.

Mistake #4: Not Starting the Y-Axis at Zero

The filled area encodes value as height. If the axis starts at 50 instead of 0, a value of 55 appears to have the same magnitude as a value of 100 (both have the same area height). This is misleading.

Mistake #5: Using Area Charts for Discrete Categories

Area charts connect data points with lines, implying continuity. If your x-axis is categorical (product names, countries, departments), use a bar chart instead. The filled area between "Apples" and "Oranges" suggests a continuous transition that doesn't exist.

How to Create an Area Chart in Minutes

You don't need Python, R, or Excel formulas. Here's how to go from raw data to a polished area chart:

Step 1: Prepare Your Data

Your data should have a time column and one or more value columns. For a stacked area chart, each value column becomes one layer.

Example CSV format:

Month,Organic,Paid,Social,Referral
Jan,12000,8000,3500,2000
Feb,13500,7800,4200,2100
Mar,15200,8200,4800,2300
Apr,17000,7500,5500,2500
May,19500,8100,6200,2800
Jun,22000,8500,7000,3000

If your data is in a spreadsheet, export it as CSV. If it's in JSON format from an API, most chart tools accept that too. See our CSV to chart tutorial for data preparation tips.

Step 2: Upload and Configure

With CleanChart, paste or upload your data, then select "Area Chart" as the chart type. The tool automatically detects your columns and maps them to the chart. Choose between simple, stacked, or 100% stacked depending on your story.

You can also use our dedicated converters:

CSV to Area Chart - Upload a CSV file directly
Excel to Area Chart - Import .xlsx spreadsheets
JSON to Area Chart - Parse API or structured data
Google Sheets to Area Chart - Import from Google Sheets

Step 3: Customize and Export

Adjust colors, labels, and axes. Follow the best practices above: start the y-axis at zero, use colorblind-safe colors, limit to 5 series, and add direct labels. Export as PNG for presentations or SVG for web use. Our export guide covers the ideal settings for each format.

Real-World Area Chart Applications

Finance: Portfolio Allocation Over Time

Investment firms use stacked area charts to show how a portfolio's allocation shifts. Stocks, bonds, real estate, and cash each form a band. The total shows portfolio value growth while the bands show rebalancing decisions. Morningstar and other financial platforms use this pattern extensively in their fund analysis reports.

Product Analytics: User Growth by Segment

Product teams track total active users as a stacked area chart: free users, trial users, and paid users. The total line shows overall growth, while the band widths reveal conversion trends. If the paid band is growing faster than free, the product is maturing well.

Climate Science: Emissions by Sector

Our World in Data uses stacked area charts to show CO2 emissions by sector (transport, industry, buildings, agriculture). These charts are cited in IPCC reports and make complex data accessible to policymakers and the public.

Web Analytics: Traffic Source Breakdown

Marketing dashboards almost universally use stacked area charts for traffic sources over time. Seeing organic search grow while paid stays flat tells a compelling SEO success story. Our time series charts guide covers more techniques for temporal data.

Frequently Asked Questions

Can I use an area chart with negative values?

Yes, but carefully. Area charts can extend below zero, but stacked area charts with negative values become confusing. If you have a mix of positive and negative values, consider a bar chart instead, or split positive and negative into separate charts.

How many data points should an area chart have?

Area charts work best with 7-50 data points on the x-axis. Fewer than 7 and the trend isn't meaningful. More than 50 and the chart may need aggregation (weekly instead of daily, quarterly instead of monthly). For very long time series, see our time series guide.

Should I use a stacked area chart or multiple line charts?

Stacked area if the total matters and you have 3-5 series. Multiple line charts (small multiples) if you need to compare individual trends precisely or have 6+ series. The stacked format emphasizes the whole; separate charts emphasize parts.

What's the difference between an area chart and a bar chart?

Both show magnitude. Bar charts are better for comparing discrete categories. Area charts are better for continuous data (time series) where you want to show the flow and accumulation of values. If your x-axis is time, area charts are usually the better choice. If your x-axis is categories, go with bars.

Are area charts accessible?

They can be, with proper design. Use sufficient color contrast between stacked layers, add direct labels, and provide the underlying data table for screen readers. Avoid relying on color alone to distinguish series. Our accessibility guide has detailed recommendations.

Create Area Charts from Your Data

Upload your CSV, Excel, or JSON data and get a polished area chart in seconds. Stacked and 100% stacked included.

Try CleanChart Free

Chart Makers

Area Chart Maker - Create area charts from your data
Line Chart Maker - Trend lines without fill
Bar Chart Maker - Compare categories
Pie Chart Maker - Show parts of a whole
Donut Chart Maker - Pie chart alternative with center display
Scatter Chart Maker - Correlation analysis
CSV to Area Chart - Convert CSV data
Excel to Area Chart - Import Excel files
JSON to Area Chart - Parse JSON data
Google Sheets to Area Chart - Import from Sheets

External Resources

Wikipedia: Area Chart - History and formal definition
Our World in Data: Energy Mix - Excellent stacked area chart examples
D3.js - Open-source library for building custom area charts
ColorBrewer - Free tool for choosing accessible color palettes
Edward Tufte - Foundational work on data-ink ratio and chart design
Storytelling with Data - Cole Nussbaumer Knaflic on when area charts work best

Last updated: February 1, 2026