Aspect ratio calculation explained

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Accepted Answer

Aspect ratio represents the proportional relationship between width and height:

**What it means**:
- **16:9** means "for every 16 units wide, there are 9 units tall"
- It's always width-to-height, never reversed
- The ratio stays constant regardless of actual size

**Why we calculate it**:
1. **Maintain proportions** when scaling images/videos
2. **Prevent distortion** when resizing
3. **Ensure compatibility** across different displays
4. **Match specifications** for platforms (Instagram 1:1, YouTube 16:9)

**Mathematical basis**:
Aspect Ratio = W/H = W:H (simplified)

**Example breakdown**:
- Original: 3840 × 2160 pixels
- Divide both by GCD (120): 32 × 18
- Simplify further (÷2): 16 × 9
- Final ratio: **16:9**

This means the width is 1.78× the height (16÷9=1.78), creating a widescreen rectangle.

**Understanding the Concept:**

**Think of it like a recipe:**
- A 16:9 ratio is like saying "mix 16 cups of width with 9 cups of height"
- Doesn't matter if you use small cups or large buckets
- The **proportion** stays the same

**Visual Explanation:**

**16:9 aspect ratio:**
- If you divide the width into 16 equal parts
- The height will be exactly 9 of those parts
- Example: 1920 pixels ÷ 16 = 120 pixels per "part"
- Height: 120 × 9 = 1080 pixels

**Real-World Analogies:**

**Pizza slices:**
- 16:9 is like cutting a pizza into 16 slices wide and 9 slices tall
- Whether it's a small pizza or large pizza, the slice pattern is the same

**LEGO bricks:**
- A 16:9 ratio is like arranging bricks 16 studs wide by 9 studs tall
- Scale up or down, the proportion remains

**Why Simplification Matters:**

**Before simplification**: 1920:1080
- Correct, but cumbersome
- Hard to recognize at a glance

**After simplification**: 16:9
- Clean, recognizable
- Industry standard format
- Easy to compare with other ratios

**Common Calculations Explained:**

**1. From dimensions to ratio:**
1920 × 1080 → Find GCD (120) → 16:9

**2. From ratio to dimensions:**
16:9 at 1080p height → (16/9) × 1080 = 1920 width

**3. From ratio to decimal:**
16:9 → 16 ÷ 9 = 1.78:1

**4. Comparing ratios:**
- 16:9 = 1.78:1
- 4:3 = 1.33:1
- 21:9 = 2.33:1
(Wider number = wider screen)

**Practical Applications:**

**Video editing:**
- Export settings must match aspect ratio
- 1920×1080, 2560×1440, 3840×2160 all work for 16:9

**Photography:**
- Crop to specific aspect ratios for printing
- 3:2 for standard photos, 4:5 for Instagram

**Web design:**
- Responsive images maintain aspect ratio
- Prevents stretching/squashing

**Display shopping:**
- Compare screen shapes by aspect ratio
- 16:9 vs 21:9 vs 32:9

Aspect ratio calculation explained

Understanding the Concept:

Think of it like a recipe:

Visual Explanation:

16:9 aspect ratio:

Real-World Analogies:

Pizza slices:

LEGO bricks:

Why Simplification Matters:

Common Calculations Explained:

1. From dimensions to ratio:

2. From ratio to dimensions:

3. From ratio to decimal:

4. Comparing ratios:

Practical Applications:

Video editing:

Photography:

Web design:

Display shopping:

Related Resources

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