PercentBox
PercentBox

About PercentBox

PercentBox is a free online percentage calculator designed to be faster and cleaner than cluttered ad-heavy tools. We focus on the math people actually need: what is X% of Y, reverse percentages, increases and decreases, percentage change, tips, and discounts.

Everything runs in your browser. There is no account, no tracking login wall, and calculation history stays on your device via localStorage. Results update as you type so you can explore numbers without friction.

Who it is for

  • Students checking homework and exam-style percent problems
  • Shoppers comparing discounts and sale prices
  • Diners splitting tips and bills
  • Anyone who needs a reliable percent increase or change

Our approach

We publish clear formulas, worked examples, and FAQ content so answers are transparent—not a black box. The site is mobile-first, lightweight, and built with modern web standards for speed and accessibility.

Start with the main percentage calculator or jump to a specialized tool below.

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