Percentage Calculator

Calculate percentages, find what percent one number is of another, and compute percentage changes — all with instant results.

Whether you're working out a tip, figuring out a discount, analyzing data changes, or solving a math problem, percentages are everywhere. This calculator handles the three most common percentage questions: what percent is X of Y, what is X% of Y, and what's the percentage change from X to Y. Switch between modes with tabs, and results update instantly as you type. Everything runs in your browser — no data leaves your device.

Find what percentage one number is of another.

X (part)

Y (whole)

Find what a given percentage of a number is.

X (%)

% of

Y (number)

Find the percentage increase or decrease between two numbers.

From (old value)

To (new value)

Enter Calculate Esc Clear Ctrl+S Copy

Quick Answer

Percentage Calculator is a Calculate percentages, ratios, and percentage changes. Three modes: X% of Y, X is what % of Y, % change from X to Y. by ThinkaBell. It runs all processing happens locally in your browser — no sign-up, no file uploads, and no data ever leaves your device.

Feature: Calculate percentages, ratios, and percentage changes
Feature: Three modes: X% of Y, X is what % of Y, % change
Feature: Privacy-first — all calculations run in your browser
Feature: Free to use with no account or registration required
Privacy-first: no data collection, no tracking, no uploads.
Free forever: no premium tiers, no hidden charges, no accounts.

Key Terms

Web Application: A web application that runs entirely in your browser using HTML, CSS, and JavaScript. No software installation, no account creation, and no file uploads to external servers.
Client-Side Processing: All calculations and data processing happen on your device. Your information never leaves your browser, ensuring complete privacy and security.
Calculators: A utility accessible through a web browser at no cost. ThinkaBell tools are free with no premium tiers, no usage limits, and no account requirements.