About Calcowa
Calcowa makes working-time calculators that show their math. Here's who's behind them and how they're checked.
Updated October 8, 2026
Who runs Calcowa
Calcowa's founded, built and edited by Muhammad Younus, a web developer and SEO specialist who's spent years building websites and web tools for clients around the world. He started Calcowa because too many calculator sites hand you a number with no explanation, and some of them are simply wrong.
Why working time
When we tested the hour calculators people use most, we found ones that broke on shifts crossing midnight, ones that dropped minus signs, and ones that charged night pay on a day shift. We'd prefer one tool that's right to fifty that are almost right, so Calcowa now focuses on working time: hours, breaks, time cards and overtime, in English and in Portuguese.
How every calculator is checked
Each rule's read from the law itself, not from someone's summary of it. For US overtime that's 29 U.S.C. section 207; for Brazil it's the CLT published by the government. The calculation engine runs dozens of automatic tests against answers worked out by hand before every update, and every result on the page shows its own math so you can check it too. If you find a mistake, email contact@calcowa.com and we'll fix it.
How the site's paid for
Calcowa's free, and it's supported by ads served by Google AdSense. We don't place ad units inside the calculator (Google positions its automatic ads itself), and the hours or pay you type aren't used for ads, because they don't leave your browser. The privacy policy has the details.
What we won't do
We won't put a calculator behind a sign-up, we won't ask for your email to show you a result, and we won't publish a tool we haven't tested. If a rule's unclear or varies by state, we'll say so on the page instead of guessing. That's a promise we're going to keep, so if you ever catch us slipping, let us know.