How to Calculate Percentages (Formulas & Examples)
The word percentage originates from the Latin phrase per centum, meaning “by the hundred”. It represents a ratio or number expressed as a fraction of 100. Calculating percentages is a foundational skill used in daily retail discounts, taxation (GST/VAT), academic grade evaluation, and personal finance.
1. Percentage of a Number
Used to find a portion of a total, such as sales tax or loan interest.
Formula: (P ÷ 100) × Total
2. Percentage Proportion
Used to determine how much one quantity represents relative to another.
Formula: (Part ÷ Total) × 100
3. Percentage Change
Measures relative growth, price inflation, or markdown between two values.
Formula: ((New - Old) ÷ Old) × 100
Where are Percentages Used Every Day?
- ✓Indian GST Calculations: Split 5%, 12%, 18%, or 28% tax rates on invoices and retail billing.
- ✓Exam Marks & Cutoffs: Converting marksheet totals (e.g. 480/600) into CBSE or college percentage scores.
- ✓Retail Shopping Discounts: Calculating final checkout costs during 20% to 50% discount sales.
- ✓Salary Appraisals & Inflation: Assessing annual raise percentages and real purchasing power changes.