Sunil Arora

I’m Sunil. By day I work in the IT industry as a technical and data architect — designing systems that move, store and make sense of large amounts of data. Outside work I like playing with numbers: I’m the person who rebuilds the bank’s interest calculation in a spreadsheet just to see if it matches.

CalciTools started from that habit. Most online calculators give you an answer and no way to check it. I wanted tools that show their working — the formula, the inputs and the assumptions — so you can see exactly where a number comes from.

What I build here

• Money calculators — income tax, take-home pay, 401(k), student loans, home buying and more, built on the 2026 figures published by the IRS and other agencies.
• 3D printing calculators — print cost, pricing, Etsy fees, filament and electricity, for people who print for fun or sell what they make.
• Everyday tools — percentages, age, tips and discounts.

How I make sure the numbers are right

My day job is about getting data right, so I treat the calculators the same way. Every calculation lives in a separate, tested module: each one has hand-worked test cases that must pass before a change goes live, and each page lists the official sources its figures come from. When tax brackets, limits or fees change, the pages are updated and the date shown on them changes too.

I’m not a tax professional or financial adviser, and the calculators are estimates for planning — not advice. If you find a mistake, please tell me at contact@calcitools.com; corrections are logged on the methodology page.