Tool Percentage Calculator

Calculate percentages, increase, decrease and percentage change

Percentage Calculation Formulas

1. What is X% of Y?

Result = (X ÷ 100) × Y

Example: What is 15% of 20? = (15 ÷ 100) × 20 = 3

2. X is what % of Y?

Result = (X ÷ Y) × 100

Example: 5 is what % of 20? = (5 ÷ 20) × 100 = 25%

3. Percentage change

Change = ((New Value - Old Value) ÷ Old Value) × 100

Example: From 100 to 120 = ((120 - 100) ÷ 100) × 100 = 20% increase

4. Percentage increase

Result = Number + (Percentage × Number ÷ 100)

Example: 100 increased by 20% = 100 + (20 × 100 ÷ 100) = 120

5. Percentage decrease

Result = Number - (Percentage × Number ÷ 100)

Example: 100 decreased by 20% = 100 - (20 × 100 ÷ 100) = 80