Analyzing Data with Stacked Area Chart and 100% Stacked Chart

1️⃣ What Is a Stacked Area Chart?

A Stacked Area Chart shows:

• The total value over time
• The contribution of each category to that total

It combines:

• Area chart
• Multiple data series stacked on top of each other

2️⃣ Example Dataset: Revenue by Product

| Month | Product A | Product B | Product C |
|-------|-----------|-----------|-----------|
| Jan   | 1000      | 800       | 600       |
| Feb   | 1200      | 900       | 700       |
| Mar   | 1500      | 1100      | 900       |
| Apr   | 1700      | 1300      | 1000      |
| May   | 2000      | 1500      | 1200      |

3️⃣ What the Stacked Area Chart Shows

From this data, a stacked area chart shows:

• Total revenue each month
• How much each product contributes
• Whether one product is growing faster

For example:

January Total = 1000 + 800 + 600 = 2400

May Total = 2000 + 1500 + 1200 = 4700

You can visually see:

• Total revenue growth
• Product A growing strongly
• Product C increasing steadily

4️⃣ When to Use a Stacked Area Chart

Use it when:

• You want to show total growth
• You want to show contribution of categories
• You want to see overall volume change

It answers:

• Is the total increasing?
• Which category contributes most?
• Is one category shrinking?

5️⃣ What Is a 100% Stacked Area Chart?

A 100% Stacked Area Chart shows:

• Percentage contribution of each category
• Relative comparison
• Composition change over time

Unlike normal stacked area:

• It does NOT show actual totals
• It shows percentages only

6️⃣ Example Dataset (Same Data, But Viewed as Percentage)

| Month | Product A | Product B | Product C |
|-------|-----------|-----------|-----------|
| Jan   | 42%       | 33%       | 25%       |
| Feb   | 43%       | 32%       | 25%       |
| Mar   | 43%       | 31%       | 26%       |
| Apr   | 43%       | 33%       | 24%       |
| May   | 43%       | 32%       | 25%       |

(Percentages calculated from total revenue each month)

7️⃣ What the 100% Stacked Chart Shows

It helps you analyze:

• Market share changes
• Category dominance
• Composition stability

From the table above, you can see:

• Product A consistently around 43%
• Product C slightly fluctuates
• Overall composition remains stable

8️⃣ Key Difference Between the Two

| Feature | Stacked Area Chart | 100% Stacked Area Chart |
|----------|-------------------|-------------------------|
| Shows actual totals | Yes | No |
| Shows percentages | No | Yes |
| Shows growth in volume | Yes | No |
| Shows proportion change | Yes | Yes |
| Best for revenue analysis | Yes | Limited |
| Best for market share | Limited | Yes |

9️⃣ When to Use Each Chart

🔹 Use Stacked Area Chart When:

• You care about total growth
• Revenue amount matters
• Budget totals matter

🔹 Use 100% Stacked Chart When:

• You care about proportions
• Market share matters
• Composition matters more than totals

🔟 How to Insert in Excel

1. Select your data
2. Go to Insert Tab
3. Choose:

• Stacked Area
• 100% Stacked Area

No formulas required.

1️⃣1️⃣ Business Example: Market Share Analysis

Imagine three companies competing:

| Year | Company A | Company B | Company C |
|------|------------|------------|------------|
| 2020 | 40%        | 35%        | 25%        |
| 2021 | 45%        | 30%        | 25%        |
| 2022 | 50%        | 28%        | 22%        |
| 2023 | 55%        | 25%        | 20%        |

A 100% stacked chart clearly shows:

• Company A gaining dominance
• Company B shrinking
• Company C declining

1️⃣2️⃣ Analysis Questions to Ask

| Question | Why It Matters |
|-----------|----------------|
| Is total increasing? | Business growth |
| Which category dominates? | Competitive strength |
| Is composition changing? | Market shift |
| Is one category shrinking? | Risk indicator |
| Are contributions stable? | Business consistency |

1️⃣3️⃣ Common Beginner Mistakes

• Using stacked chart with too many categories
• Using 100% chart when totals matter
• Ignoring axis labels
• Not adding legends
• Using too many colors

1️⃣4️⃣ Visual Comparison Example

Imagine:

Total revenue doubled, but proportions stayed same.

Stacked Area Chart:

• Shows total doubling

100% Stacked Chart:

• Looks identical (because proportions didn’t change)

This is very important to understand.