Image Dimension & Aspect Ratio Calculator
Calculate exact aspect ratios (16:9, 4:3, 1:1), proportional width/height scaling, and megapixel counts for any resolution.
How the Image Dimension & Aspect Ratio Calculator works
Calculate exact aspect ratios (16:9, 4:3, 1:1), proportional width/height scaling, and megapixel counts for any resolution. Below is the exact mathematical or algorithmic model used by this resize & aspect ratio utility, along with its key operating assumptions.
Aspect Ratio = Width ÷ GCD(Width, Height) : Height ÷ GCD(Width, Height).Step-by-step workflow
- Select a PNG, JPEG, or WebP file from your device or enter source resolution dimensions in the Image Dimension & Aspect Ratio Calculator panel.
- The browser's HTML5 Canvas and GCD resolution engine processes Aspect Ratio = Width ÷ GCD(Width, Height) : Height ÷ GCD(Width, Height). entirely in local memory.
- Compare original vs. optimized file sizes or aspect-ratio locked dimensions and download the output directly.
Worked example & key advantages
Verify that a 2560×1440 display or image is a true 16:9 aspect ratio (3.69 MP).
Why use this Image Dimensions tool
- Hardware-accelerated HTML5 Canvas processing—your personal photos and design assets never leave your device.
- Supports modern WebP, PNG, and JPEG transcoding with adjustable quality and max-width downscaling.
- Exact Euclidean GCD aspect-ratio locking to prevent stretched or blurred responsive images.
Important Assumptions & Scope
- Uses Euclidean Greatest Common Divisor (GCD) math.
Frequently Asked Questions — Image Dimensions
Clear answers to common questions about methodology, edge cases, and privacy.
How are megapixels calculated from width and height?
Multiply pixel width by pixel height and divide by 1,000,000 (for example, 1920 × 1080 = 2,073,600 pixels ≈ 2.07 MP).
Are my images uploaded to any cloud server during processing?
Never. The Image Dimension & Aspect Ratio Calculator decodes and re-encodes images directly inside your browser using the HTML5 Canvas API and local Blob URLs, ensuring complete privacy and zero upload latency.
Does client-side conversion strip EXIF metadata automatically?
Yes. Rendering an image onto an HTML5 Canvas and exporting a new JPEG, PNG, or WebP file naturally strips embedded camera EXIF and GPS location metadata.