Author & Founder
Samir Messaoudi
Founder of UseACalculator.com — builder of every calculator and author of every guide on this site.
Samir is a software engineer who started UseACalculator.com after getting tired of financial tools that spit out a number without explaining what it means for the decision in front of you. He designs, codes, and maintains every one of the 323 calculators on this site personally — from the underlying formulas to the interface — and writes the guides that accompany them.
His approach is engineering-first: every tool is built on established, verifiable methods — the same debt-to-income thresholds conventional lenders use, standard amortization mathematics, published IRS and USDA figures, and widely accepted health formulas — with the assumptions stated right in the interface rather than buried in fine print. When the underlying standards change, the tools are updated and the update is dated on the page.
Samir is not a licensed financial advisor, physician, or attorney, and nothing on this site is personalized professional advice. The goal of every tool here is more modest and, he'd argue, more useful: show you the real numbers behind a decision clearly enough that you can reason about it yourself — and know when a question is big enough to bring to a professional.
323
Calculators built
345
Guides written
How the work is checked
Every calculator's methodology, key assumptions, and worked examples are published on its own page so the math can be independently verified. The full standards this site holds itself to — sourcing, updates, corrections, and how the site makes money — are documented in the editorial policy. If you find an error in any tool or guide, reporting it is genuinely appreciated.