Percentage Calculator

Solve every percentage question — of, increase, decrease, and what-percent-of.

%
50% of 200
100.00

About the Percentage Calculator

Percentages come up constantly — exam marks, discounts, salary hikes, GST, tips, statistics — and the AlarmDaddy Percentage Calculator handles every common variant in one place. It answers "what is X% of Y", "X is what percent of Y", "what is the percentage increase or decrease from X to Y", and adds or subtracts a percentage from a number.

Pick the type of percentage question, enter your two numbers, and read the answer instantly with the working shown. Whether you are figuring out your exam percentage, the percentage change in a stock, the markup on a product, or how much a 15% hike adds to your salary, this calculator covers it without you having to remember which way to divide.

How to use this calculator

  1. 1Choose the type of percentage calculation you need.
  2. 2Enter the two numbers.
  3. 3Read the answer with the working shown.

The formula

X% of Y = (X/100) × Y; X is what % of Y = (X/Y) × 100; % change = ((new − old)/old) × 100.

The calculator selects the right formula for the question type. "Percentage of" multiplies the fraction by the base. "What percent" divides the part by the whole. "Percentage change" measures the difference relative to the original value, giving a positive number for an increase and negative for a decrease.

Frequently asked questions

Use the "X is what percent of Y" mode: enter your marks obtained as X and the total marks as Y. The result is your percentage.