Guide

What is Percentage? Complete Guide 2025 (Definition, History & Uses)

January 18, 2025

10 min read

By Tools Team

You see them everywhere: on sale tags, in weather forecasts, on battery indicators, and in tax returns. But what is percentage exactly?

At its simplest, a percentage is a way of expressing a number as a fraction of 100. It is a universal language for comparing quantities, measuring change, and understanding proportions. In this article, we’ll dive deep into the definition, explore the fascinating history behind the symbol, and look at how percentages shape our modern world.

Definition: What Does "Percent" Mean?

The word "percent" comes from the Latin phrase "per centum", which literally translates to "by the hundred" or "for every hundred."

Mathematically, a percentage is a dimensionless number used to express a ratio.

Symbol: %
Example: 50% means 50 out of 100, or the fraction 50/100, or the decimal 0.50.

The History of Percentage

Ancient Rome

Long before the decimal system existed, Ancient Roman computations were often made in fractions of 1/100. Emperor Augustus levied a tax known as centesima rerum venalium—a 1/100 tax on goods sold at auction.

Evolution of the Symbol (%)

The "%" symbol evolved from scribal abbreviations of the Italian term per cento. It started as "p 100", then "p cento", and eventually the "100" morphed into the two circles and slash we use today.

Uses of Percentage in Daily Life

Finance & Business

Interest Rates (APY)
Discounts (40% OFF)
Taxes (Sales tax, Income tax)

Health & Fitness

Body Fat Percentage
Nutritional Labels (% Daily Value)
BMI (Body Mass Index)

Technology

Battery Life (15% remaining)
Download Progress (85% complete)

Statistics

Election Results
Weather Forecasts (30% chance of rain)

Understand Your Health Stats

Percentages help you understand nutrition and fitness. Use our BMI calculator to get a baseline for your health journey.

Frequently Asked Questions

Who invented the percentage symbol?

It evolved over centuries. Italian mathematician Luca Pacioli (1494) is often credited with formalizing the use of percentages in commercial arithmetic.

Is percent the same as percentile?

No. Percent is a portion of a whole. Percentile compares your score to others (e.g., being in the 80th percentile means you scored better than 80% of people).

Can you have a percentage greater than 100?

Yes. If something grows beyond its original size, it exceeds 100%. For example, if revenue triples, it has grown by 200% and is now 300% of its original size.