About

About pctzen

pctzen is a free, no-signup percentage calculator. It answers the three percent questions people actually ask — what is X% of Y, X is what percent of Y, and the percent change from X to Y — showing the working formula under each result.

Two everyday modes sit alongside it: a discount mode that shows you saves and final price, and a tip mode for splitting bills.

Everything runs in your browser. Your numbers never leave your device — no account, no tracking, no server-side storage.

We built it for shoppers, students, tippers and forecasters who just want the honest percent, fast.