Percentage Calculator

Percentages are used everywhere — from discounts and tips to interest rates and statistics. Understanding how to calculate percentages helps you make better financial decisions.

Key Terms

Percentage — A fraction of 100, represented by the symbol %.
Base Value — The whole amount you're calculating a percentage of.
Rate — The percentage being applied.
Part — The portion of the base value represented by the percentage.

Common Percentage Formulas

Percentage = (Part / Whole) × 100
Part = (Percentage / 100) × Whole
Whole = Part / (Percentage / 100)

Common Uses

Discounts — Calculate sale prices and savings
Tips — Calculate gratuity at restaurants
Tax — Calculate sales tax or income tax
Interest — Calculate loan or investment interest
Change — Calculate percentage increase or decrease

Tips for Percentage Calculations

To find 10% of any number, move the decimal point one place left
To find 5%, find 10% and divide by 2
To find 15%, find 10% and add half of it
Percentage increase and decrease use the same formula: (New - Old) / Old × 100
A 50% increase followed by a 50% decrease doesn't return to the original value