The latest articles on DEV Community by Astro (@astrodevkit). https://dev.to/astrodevkit https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4207366%2Fbebf892b-37ad-4c4a-8e7f-b053bee14917.png https://dev.to/astrodevkit en Astro Sun, 25 Oct 2026 21:53:41 +0000 https://dev.to/astrodevkit/devkit-a-one-file-calculator-library-with-tested-formulas-now-with-an-llm-cost-calculator-4c8k https://dev.to/astrodevkit/devkit-a-one-file-calculator-library-with-tested-formulas-now-with-an-llm-cost-calculator-4c8k <p>I kept reaching for a quick calculator and landing on pages crowded with ads, pop-ups, and distractions. So I built the tool I wanted instead: a lean calculator site that gets out of the way.</p> <p>DevKit is a one-file calculator library with 69 tools, all running client-side in your browser. The tools are organised into tabbed pages, so you can find the one you need without scrolling through a long list.</p> <h2> What's new: an LLM cost calculator </h2> <p>The newest addition is for anyone working with language models. The LLM cost calculator helps you estimate what a request will cost, and the tokens/sec simulator shows how generation speed affects timing. It's the part I reach for most when I'm planning an LLM feature and want a quick sense of cost and speed before writing code.</p> <h2> Verified formulas </h2> <p>A calculator is only useful if you can trust its answers, so the formulas in DevKit are verified with tests. That gives me a way to catch mistakes when a formula changes, instead of hoping the numbers look right.</p> <h2> Try it </h2> <p><a href="https://astro-devkit.github.io/devkit/" rel="noopener noreferrer">Try DevKit here</a></p> <p>What calculator should I add next? Let me know in the comments — I'd love to hear what you'd actually use.</p> showdev webdev javascript ai