About ToolsCloset

ToolsCloset is a growing collection of free online calculators, built by one developer who wanted tools that are fast, private and honest about how they work.

Hi, I’m Shah Rukh

I’m an all-rounder software developer from Lahore, Pakistan. I work across the whole stack: designing clean interfaces, writing the logic behind them, working with databases, and deploying and maintaining live websites. I enjoy the full journey of taking an idea, building it properly, and putting it in front of real people.

I built ToolsCloset because I kept running into calculator sites that were slow, buried under pop-ups, or gave an answer without explaining where it came from. As a developer, I knew these tools could be simple, quick and transparent, so I started building my own. I design, code, test and write every page on this site myself.

What I work with

• Front-end: HTML, CSS and JavaScript, with a focus on fast, mobile-friendly and accessible pages.
• Back-end and data: server-side logic, APIs and databases.
• Deployment: hosting, domains, performance and security for live websites.
• SEO and content: writing clear, well-structured pages that answer real questions.

What makes ToolsCloset different

• Every result is explained. Each tool page shows the formula it uses and a worked example, so you can check the answer yourself.
• Standard, trusted methods. Health tools follow World Health Organization (WHO) and CDC categories. Education tools use the standard GPA and CGPA methods, and point out where universities differ.
• Your data stays with you. All calculations run inside your browser. The numbers you type are never sent to or stored on a server.
• Built to be fast. No heavy frameworks and no unnecessary scripts, so pages load quickly even on slow mobile connections.

How I build and test each tool

Before a calculator goes live, I write automated tests that check its maths against known answers and edge cases, such as leap-year birthdays, zodiac sign boundary dates and unit conversions. I also test each page on phones and desktops. When official guidance changes, I update the page and its “last updated” date.

What’s next

I’m adding new calculators regularly, from everyday maths to health and student tools. If there’s a calculator you wish existed, I’d genuinely like to hear about it.

Get in touch

Found a mistake, have a suggestion, or just want to say hello? Email me at [email protected] or visit the contact page. I read every message, and confirmed errors get fixed quickly.