percent Percentage Calculator

About the Percentage Calculator

Our free online percentage calculator helps you quickly solve common percentage problems. Whether you need to calculate tips, discounts, tax amounts, percentage increases, or percentage changes, this tool makes it simple and fast.

How to Calculate Percentages

This calculator supports five common percentage calculations:

• What is X% of Y? — Multiply Y by X/100. For example, 20% of 150 = 150 × 0.20 = 30
• X is what % of Y? — Divide X by Y and multiply by 100. For example, 30 is what % of 150 = (30 ÷ 150) × 100 = 20%
• Percentage Change — Calculate the increase or decrease between two values using the formula: ((New - Old) ÷ Old) × 100
• Increase by % — Add a percentage to a value. Formula: Value × (1 + Percent/100). For example, 100 increased by 25% = 100 × 1.25 = 125
• Decrease by % — Subtract a percentage from a value. Formula: Value × (1 - Percent/100). For example, 100 decreased by 25% = 100 × 0.75 = 75

Common Uses

• Calculating tips at restaurants (15%, 18%, 20%)
• Finding sale prices and discounts
• Determining tax amounts
• Calculating grade percentages
• Analyzing growth rates and changes
• Computing price increases or decreases
• Financial calculations and budgeting

Percentage Increase/Decrease Formula

To calculate a percentage increase or decrease:

• Increase: New Value = Original × (1 + Percentage/100)
• Decrease: New Value = Original × (1 - Percentage/100)

For example, if a $80 item is marked up by 15%: $80 × 1.15 = $92

If a $200 item is discounted by 30%: $200 × 0.70 = $140