Usman Ali is the founder of HarborsCalculators and a software engineer specializing in full-stack website development. He designs, builds, tests and writes every calculator on the site, with about eight years in web development and SEO behind it.
Experience
He started taking freelance web development work in 2018 and has been building for clients since. Most of what he knows came from doing the work, and from Udemy courses taken alongside it. The Software Engineering degree came later, at Superior University in Lahore, finishing in 2026, and it filled in the theory behind things he had already shipped.
Much of that time went into WordPress and Shopify theme development, with frontend and design work throughout. He has built blogging sites and SaaS platforms, and the two teach different lessons. A blog teaches you what makes a page findable and worth reading once somebody lands on it. A SaaS product teaches you that the thing has to keep working months after launch, on other people's devices, with data nobody planned for.
These days the work is mostly Astro and modern frontend tooling, which is what HarborsCalculators runs on.
HarborsCalculators
He built it because the calculators he kept landing on handed him a number and stopped there. No formula, no assumptions, no way to see what happens in year seven, and no way to work out why the figure disagreed with the one his bank had given him.
So every calculator here shows its working. You get the formula in plain terms, the assumptions written out rather than buried, the full schedule payment by payment, and the whole thing as a PDF, an image, a spreadsheet or a CSV. Take it away and check it against whatever your lender sends you.
Mathematics and programming held his attention long before either paid for anything, and that shows up in how the work gets done. Every formula is taken from a primary source and covered by unit tests that run before anything ships, rather than copied from another calculator and assumed right. The downloads are checked by opening the generated files and reading them back, because code running without an error is not evidence that the file it wrote is correct.
The methodology sets all of that out, including what the numbers cannot cover, and the editorial policy covers what gets published and what gets cut.