16:9
AspectRatioKit
About AspectRatioKit

Engineered for Precision & Absolute Privacy

AspectRatioKit was built to replace ad-cluttered, slow calculator utilities with a clean, client-side, developer-grade toolkit.

Our Mission

Modern creators frequently jump between image editors, video timelines, and responsive CSS stylesheets. Every day, designers and video editors need to calculate missing dimensions, check whether an image fits 16:9 or 4:3 without letterboxing, or convert photo print inches into 300 DPI pixels.

Unfortunately, traditional online calculators are laden with invasive tracking cookies, banners, and slow server uploads. We created AspectRatioKit with a single foundational standard: 100% of mathematical computation and image analysis must occur locally on your machine.

01

Zero Server Uploads

Your photos, graphics, and video thumbnails are inspected via HTML5 Canvas and FileReader APIs in browser memory. No data is ever transmitted across the network.

02

Mathematical Rigor

Ratios are simplified using the Euclidean Greatest Common Divisor algorithm, giving exact integer proportions without rounding errors.

03

Zero Clutter & Distraction

No popups, paywalls, or third-party ads. Designed following the Geist aesthetic with instant keyboard navigation and theme toggle support.

How the Platform Is Built

AspectRatioKit is built on Astro for static site generation, ensuring instant page loads with minimal client JavaScript overhead. Styling is powered by Tailwind CSS v4 and the Geist design system, providing dark mode support, fluid responsive layouts, and accessible UI controls.

HTML5 Canvas APIEuclidean GCD AlgorithmAstro SSGTailwind CSS v4Client-Side Memory Execution

Have feedback or suggestions?

We are constantly adding new ratio presets and visual tools for creators.