How to Calculate Percentages?
Calculating percentages is one of the most fundamental math skills. There are three main types of percentage questions:
1. What is X% of Y?
Question: "What is 20% of $500?"
Result = (X ÷ 100) × Y = (20 ÷ 100) × 500 = $100
2. X is what percent of Y?
Question: "$80 is what percent of $400?"
Percent = (X ÷ Y) × 100 = (80 ÷ 400) × 100 = 20%
3. Percentage Change
Question: "Price rose from $100 to $120 — what's the percentage increase?"
Change% = ((New − Old) ÷ Old) × 100 = ((120−100) ÷ 100) × 100 = 20%
Real-World Examples
- Store discount: $200 item, 15% off → Save $30, pay $170
- Sales tax: $1,000 + 8% tax = $1,080
- Interest: $10,000 at 6% annual = $600 interest
Related Calculators: