Composition tools

Composition tools support the spatial-decision side of design: aspect ratios for video and images, golden ratio proportions for layouts, image dimension calculations for responsive design, and DPI/PPI conversion for print work. Each is a simple calculation that's easy to get wrong by hand under deadline pressure.

The aspect ratio calculator resizes a width or height while preserving a target ratio (16:9, 4:3, 1:1, 21:9 cinemascope, or any custom ratio you type). Useful when scaling videos for different platforms (YouTube wants 16:9, Instagram Reels wants 9:16, Twitter wants 16:9 or 1:1 depending on placement) and when computing the matching height for a fixed-width responsive image. The golden ratio calculator returns the φ-related companion of any number — split a width into two φ-related parts for a layout, or divide a layout area into nested golden rectangles.

The image dimension calculator computes the new height when you resize a width while preserving aspect ratio (the math behind the most-used resize operation). The DPI / PPI converter handles print-vs-screen: a 1000-pixel-wide image at 72 PPI is about 14 inches wide on screen but only about 3.3 inches at 300 DPI for print. Important for prepress: under-resolved print output looks pixelated; over- resolved screen output wastes bandwidth. The converter shows the print size for a given pixel count and DPI, and the pixel count needed for a target print size.