About QuickUse

QuickUse Calculator is a growing library of fast, accurate online calculators. We built it because the biggest calculator sites are cluttered, slow, and noisy. We wanted something cleaner.

Every calculator is designed to give you an answer in under a second, with enough context below to understand what the number means — formulas, examples, sources, and the cases where the calculator might mislead you.

Every calculator has automated tests that validate outputs against known reference values — textbook examples, official regulator calculators, or cross-checks against independent tools. When a tax table updates (IRPF, INSS), we version the tables so historical calculations remain auditable.

If you find an input that produces a wrong answer, email us and we will fix it the same week.

Calculations happen entirely in your browser — we never see the numbers you enter. Favorites and history are stored on your device, not on our servers. We collect only anonymous traffic analytics (pages visited, country, browser, load times) via Vercel Analytics, without cookies. Full details in our privacy policy.

QuickUse is maintained by Thiago Bertoletti, a product manager and software engineer based in Brazil. The editorial content for each calculator is written after checking primary sources (the relevant law, the regulator documentation, academic references) and cross-validated against established calculators where possible.

For tax and labor-law calculators (IRPF, rescisão, 13º, FGTS), the content cites the exact law or regulation that drives each rule. Calculators for specialized fields (medical, legal) will carry additional credentials from qualified authors as the catalog grows.

Email: contact-us@quickusecalculator.com. We aim to reply within a few business days — faster for bug reports.