How percentages work
A percentage is a fraction of 100. To find X% of a number, multiply the number by X and divide by 100: 15% of 2,500 is 375. To increase a value by X%, add that amount; to decrease, subtract it. The same maths covers exam marks, salary hikes, discounts and GST.
Common uses
Students use it to convert marks to percentages, employees to check a hike (a 12% raise on ₹50,000 is ₹56,000), and shoppers to compare discounts. For reverse questions such as "what percent is 45 of 60", divide the part by the whole and multiply by 100, which gives 75%.
Frequently asked questions
How do I calculate percentage of marks?
Divide marks obtained by total marks and multiply by 100. 432 out of 500 is 86.4%.
What is percentage change?
(New − Old) ÷ Old × 100. Going from 80 to 100 is a 25% increase.
Is percentage the same as percentage points?
No. Moving from 10% to 12% is 2 percentage points but a 20% increase.