DataToolsLab
Units & Numbers Tools

Percentage Calculator

Calculate percentages: what is X% of Y, and what percent is X of Y.

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What is Percentages?

A percentage calculator covering the three most common queries — part-of-whole, ratio-to-percent, and percent change (increase/decrease).

How it works

Each mode applies its formula (value × percent ÷ 100, part ÷ whole × 100, and (new − old) ÷ old × 100) with results rounded to your chosen precision.

  1. Enter your input. Type or paste your input into the field above — the tool responds instantly.
  2. Review the result. Output updates live as you type. Everything runs entirely in your browser.
  3. Copy or download. Use the Copy button to grab the result, or Download to save it as a file.

Examples

Realistic sample

Paste or type any realistic input — the tool computes the result locally and instantly.

Common mistakes

Expecting a server round-trip

Nothing is uploaded — every tool in this category runs entirely in your browser.

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