How to Calculate Percentage: Easy Methods
Percentages are used daily — from calculating discounts and tips to understanding exam scores and loan interest. Here are the simplest methods to calculate percentages.
Finding Percentage of a Number
To find X% of a number: Multiply the number by X and divide by 100. Example: 15% of 200 = 200 × 15 / 100 = 30. Quick trick: To find 10%, just move the decimal point one place left. 10% of 450 = 45. For 5%, halve the 10% value.
Percentage Increase/Decrease
Formula: ((New Value - Old Value) / Old Value) × 100. If price goes from ₹200 to ₹250: ((250-200)/200) × 100 = 25% increase. If it drops to ₹150: ((150-200)/200) × 100 = -25% decrease.
Reverse Percentage
To find the original price before a discount: Original = Discounted Price / (1 - discount/100). If something costs ₹800 after 20% off: Original = 800 / 0.80 = ₹1,000.
Percentage Tips & Tricks
1) X% of Y = Y% of X (so 8% of 50 = 50% of 8 = 4). 2) To add 18% GST, multiply by 1.18. 3) To find what percentage A is of B: (A/B) × 100. 4) For exam scores: (Marks obtained / Total marks) × 100.