Percentages are used in shopping, academics, finance, and business. Once you know a few core formulas, most percentage questions become easy.
Core Percentage Formulas
- Percentage =
(Part / Whole) x 100 - Percentage increase =
((New - Old) / Old) x 100 - Percentage decrease =
((Old - New) / Old) x 100
Discount Example
If a shirt costs Rs. 2,000 and has a 25% discount:
- Discount = 2,000 x 25 / 100 = Rs. 500
- Final price = Rs. 2,000 - Rs. 500 = Rs. 1,500
Markup Example
If cost price is Rs. 800 and markup is 30%:
- Markup = 800 x 30 / 100 = Rs. 240
- Selling price = Rs. 1,040
Exam Percentage Example
If you score 420 out of 500:
- Percentage = (420 / 500) x 100 = 84%
Common Mistake to Avoid
Do not add or subtract percentage points incorrectly. A 20% increase followed by 20% decrease does not bring you back to the original value.
Use Our Percentage Calculator
Try the Percentage Calculator for instant percentage, increase, and decrease calculations.