Aspect Ratio Calculator

Calculate new image dimensions while maintaining the aspect ratio. Perfect for resizing images without distortion, whether you're optimizing for web, social media, or print.

Upload Image to Get Dimensions

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Enter Current Dimensions

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Calculate New Dimensions

Enter either new width OR new height - the other will be calculated automatically

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Common Aspect Ratios

About This Tool

The Aspect Ratio Calculator helps you resize images while maintaining their proportions. When you resize an image without maintaining aspect ratio, it becomes distorted and unprofessional. This tool ensures your images look perfect at any size.

What is Aspect Ratio?

Aspect ratio is the proportional relationship between an image's width and height, expressed as two numbers separated by a colon (e.g., 16:9). It ensures images maintain their shape when resized, preventing stretching or squashing.

Common Aspect Ratios Explained

  • 16:9 (1.78:1) - HD video, modern displays, YouTube, most TVs
  • 4:3 (1.33:1) - Traditional TV, older displays, presentations
  • 1:1 (Square) - Instagram posts, profile pictures, logos
  • 21:9 (2.33:1) - Ultrawide monitors, cinematic video
  • 3:2 (1.5:1) - 35mm film, many digital cameras
  • 9:16 (Vertical) - Instagram/TikTok stories, mobile vertical video

How to Use

  1. Upload an image OR enter current width and height manually
  2. Enter either a new width OR new height (not both)
  3. The calculator automatically computes the other dimension
  4. Use the result to resize your image without distortion

Use Cases

  • Web Design: Resize images for different screen sizes
  • Social Media: Prepare images for Instagram, Facebook, Twitter specs
  • Print: Scale images while maintaining quality
  • Video Thumbnails: Create perfectly proportioned thumbnails
  • E-commerce: Standardize product image sizes

Tips for Best Results

  • Always maintain aspect ratio when resizing for professional results
  • For web use, larger dimensions mean larger file sizes - find a balance
  • Use common aspect ratios (16:9, 4:3, 1:1) for better compatibility
  • When cropping, you may need to change aspect ratio - plan accordingly
  • Consider your display medium when choosing dimensions

Privacy & Security

If you upload an image, it's processed entirely in your browser to extract dimensions. The image is never sent to any server or stored. All calculations happen locally on your device.

Frequently Asked Questions

What happens if I change both width and height?

If you enter both dimensions, the aspect ratio will change and your image may appear stretched or squashed. It's best to enter only one dimension and let the calculator find the other to maintain proportions.

Can I use this for video?

Yes! Aspect ratios work the same for videos and images. Use this calculator to determine proper video dimensions for different platforms (YouTube 16:9, Instagram Stories 9:16, etc.).

What aspect ratio should I use for Instagram?

Instagram supports multiple ratios: 1:1 (square) for feed posts, 4:5 (portrait) for feed posts, 9:16 (vertical) for stories and reels. Use 1080×1080 for square posts, 1080×1350 for portrait posts.

How do I actually resize my image?

This calculator tells you the correct dimensions. To actually resize, use image editing software like Photoshop, GIMP, or online tools, and enter the calculated dimensions ensuring "maintain aspect ratio" is checked.