Percentage Calculator

Quickly calculate percentages, percentage change, and reverse percentage with instant results.

What is X% of Y?

Percentage (%)

Of Number

X is what % of Y?

Number (X)

Of Total (Y)

Percentage Change

Original Value

New Value

What is a Percentage Calculator?

A Percentage Calculator is a mathematical utility that solves complex fraction and ratio problems instantly. "Percent" literally translates to "per 100", meaning it represents a number as a fraction of 100. While simple percentages (like 50% being half) are easy to do in your head, calculating exact tip amounts, tax deductions, or quarterly business growth requires a dedicated calculator.

How to Use the 3 Mathematical Modes

This tool combines three distinct calculation modes into one easy interface:

What is X% of Y? Use this to find a specific cut of a larger number. Common uses include calculating a 15% tip on a restaurant bill, determining how much a 20% discount saves you on clothing, or figuring out your 8% sales tax.
X is what % of Y? (Reverse Percentage) Use this to find your percentage score. For example, if you got 45 questions right on an 80-question test, this mode tells you your exact percentage grade. It's also useful for finding out what percentage of your monthly income goes toward rent.
Percentage Change: Crucial for business and finance. Enter your original sales numbers and your new sales numbers. The calculator will instantly tell you the exact percentage of growth (profit increase) or decline (loss/discount).

Why Are Percentages Important?

We interact with percentages every day. Banks use them to calculate interest rates on your loans and mortgages. Retailers use them to communicate Black Friday discounts. By using our tool, you can verify if a "Buy 1 Get 1 50% Off" deal is mathematically better than a flat "30% Off Entire Purchase" coupon, saving you real money.

Frequently Asked Questions

How do I calculate a percentage of a number?

To find the percentage of a number, multiply the number by the percentage fraction. For example, to find 15% of 200, you calculate 200 Ã— 0.15, which equals 30. Our "What is X% of Y" tool does this instantly.

How do I calculate what percentage one number is of another?

Divide the smaller number by the total number, and then multiply by 100. For instance, if you scored 30 out of 200 on a test, you divide 30 by 200 (0.15) and multiply by 100 to get a 15% score.

What is the formula for Percentage Change?

The percentage change formula is: ((New Value - Original Value) / |Original Value|) Ã— 100. This is frequently used in finance to determine if profits went up or down compared to last year.