How to resize and keep aspect ratio?

Resizing while maintaining aspect ratio prevents distortion and stretching. Here's everything you need to know.

The Core Concept:

Method 1: Use Aspect Ratio Lock (Easiest)

Most tools have a "lock" feature that maintains proportions automatically.

In Photoshop:

1. Select the image with Rectangle Select Tool
2. Go to Image → Scale Image
3. Look for chain link icon 🔗
4. Make sure it's LINKED (connected)
5. Change width (height updates automatically)
6. Click OK

Or:

1. Edit → Free Transform (Ctrl/Cmd + T)
2. Hold Shift while dragging corner
3. Image scales proportionally
4. Press Enter

In GIMP:

1. Image → Scale Image
2. Look for chain link icon 🔗
3. Click to LINK (if not already)
4. Change one dimension
5. Other dimension updates automatically

In Canva:

1. Select image
2. Drag corner (not edge)
3. Shift + drag for perfect proportions
4. Automatically maintains ratio

Method 2: Calculate New Dimensions

If you're manually setting dimensions, use this formula:

Example:

Original image: 1920 × 1080 Want width: 800 pixels

New Height = (800 ÷ 1920) × 1080 New Height = 0.417 × 1080 New Height = 450 pixels

Result: 800 × 450 (maintains 16:9 ratio)

Method 3: Use Aspect Ratio Calculator

Our calculator handles this automatically:

1. Enter original width and height
2. Enter new width (or height)
3. Calculator shows new height (or width)
4. Maintains exact ratio

Tools with Built-In Aspect Ratio Locking:

Resizing for Different Purposes:

Resize for Web:

Original: 3000 × 2000 (3:2) Target width: 800 pixels

Resize for Social Media:

Original: 1920 × 1080 (16:9) Target: Instagram (want width 1080)

Resize for Print:

Original: 2400 × 1600 (3:2) Target: 4×6 inch print

Step-by-Step by Software:

Photoshop Image Resize:

1. Image → Image Size
2. Check chain link is CONNECTED 🔗
3. Change width to desired size
4. Height updates automatically
5. Click OK

GIMP Image Resize:

1. Image → Scale Image
2. Verify chain icon is LINKED
3. Enter desired width
4. Height calculates automatically
5. Click Scale

Video Resize (Premiere Pro):

1. Right-click clip
2. Select "Scale"
3. Select "Fit to Frame"
4. Or set width, height locks to ratio
5. Video maintains aspect ratio

Common Resizing Scenarios:

Scenario 1: Make Thumbnail

Original: 1920 × 1080 Want: 320 pixels wide

New height = (320 ÷ 1920) × 1080 = 180 Result: 320 × 180 ✓

Scenario 2: Mobile Version

Original: 2560 × 1440 Want: 480 pixels wide

New height = (480 ÷ 2560) × 1440 = 270 Result: 480 × 270 ✓

Scenario 3: Large Print

Original: 2000 × 1333 (3:2) Want: 10 inches wide (3000 pixels at 300 DPI)

New height = (3000 ÷ 2000) × 1333 = 2000 Result: 3000 × 2000 ✓

Why This Matters:

Quick Reference Table:

Common Aspect Ratio Multipliers:

If changing from full size to smaller:

Pro Tips:

Key Takeaway:

To resize while maintaining aspect ratio, use the aspect ratio lock feature (chain link icon) in your editing software. Change one dimension and the other updates automatically. This prevents distortion and maintains professional quality. If manually calculating, use the formula: New Height = (New Width ÷ Original Width) × Original Height.