Percentage Calculator

Calculate percentages, percentage change, and percentage of totals for any numbers.

Calculate percentages, percentage changes, and percentage of totals with step-by-step explanations. Perfect for students, professionals, and everyday percentage calculations.

Calculation Type

Percentage (%)

Of (total value)

Understanding Percentages

A percentage is a way of expressing a number as a fraction of 100. The word "percent" comes from the Latin "per centum," meaning "by the hundred."

Basic Percentage Formulas

Percentage of a number: (Percentage ÷ 100) × Number
What percent: (Part ÷ Whole) × 100
Percentage change: ((New Value - Original Value) ÷ Original Value) × 100
Percentage increase: Original + (Original × Percentage ÷ 100)
Percentage decrease: Original - (Original × Percentage ÷ 100)

Common Percentage Applications

Finance: Interest rates, investment returns, tax calculations
Shopping: Discounts, sales tax, tips
Statistics: Survey results, data analysis, probability
Business: Profit margins, growth rates, market share
Education: Test scores, grade calculations, improvement tracking

Percentage vs Percentage Points

Percentage: If something increases from 20% to 25%, that's a 25% increase (5/20 = 0.25).

Percentage Points: The same change is a 5 percentage point increase (25 - 20 = 5).

Common Percentage Conversions

Fraction to Percentage: (Numerator ÷ Denominator) × 100
Decimal to Percentage: Decimal × 100
Percentage to Decimal: Percentage ÷ 100
Percentage to Fraction: Percentage/100, then simplify

Tips for Mental Math

10%: Move decimal point one place left
1%: Move decimal point two places left
50%: Divide by 2
25%: Divide by 4
20%: Divide by 5

Note: Percentage calculations are rounded to appropriate decimal places for display. For financial calculations involving money, always verify results and consider rounding rules for your specific application. Some calculations may have slight variations due to rounding.