Math
Percentage Calculator
Calculate percentages, increases, decreases, discounts, taxes, tips, markup, markdown, and percentage difference.
Last updated July 9, 2026
About This Tool
Use this calculator for the percentage questions people run into every day: what X percent of Y is, what percent one number is of another, increases, decreases, markup, markdown, discounts, taxes, tips, and percent difference.
Core Percentage Formulas
part = whole x percent / 100; change% = (new - old) / old x 100The calculator switches formulas based on the selected mode. Discounts and taxes calculate the percentage amount first, then subtract or add it to the original value.
Examples
Find 25% of 500
Number: 500, Percentage: 25
Result: 125
Useful for calculating discounts or portions.
Find a discount
Original price: 80, Discount: 15%
Result: Final price: 68, Savings: 12
Calculate a tip split
Bill: 120, Tip: 18%, People: 3
Result: Total: 141.60, Per person: 47.20
FAQ
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide the result by 100.
Can this calculator handle decimals and negative changes?
Yes. Decimal values and decimal percentages are supported. Percentage change can be positive or negative depending on whether the ending value is above or below the starting value.
What is the difference between markup and markdown?
Markup compares profit to cost. Markdown compares a price reduction to the original price.