Percentage Calculator
Calculate percentages of any amount. Find what percent one number is of another or solve percent equations.
Calculate percentages, find what percent one number is of another, or add/subtract percentages from values.
How to Use
Understanding Percentages
A percentage is a way to express a number as a fraction of 100, denoted by the % symbol. For example, 25% means 25 out of 100, or a quarter of the whole. Percentages help you compare proportions when dealing with different scales or sizes.
Common Percentage Problems:
- What is P% of X? - Find a percentage of a number (tips, discounts)
- Y is what % of X? - Find what percentage one number is of another
- Y is P% of what? - Find the whole when you know a part and percentage
- X + P% - Add a percentage (taxes, markups)
- X - P% - Subtract a percentage (discounts, sales)
Converting Between Forms:
- Decimal to Percent: Multiply by 100 (0.44 × 100 = 44%)
- Percent to Decimal: Divide by 100 (15.6% ÷ 100 = 0.156)
- Fraction to Percent: Divide, then multiply by 100 (4/5 = 0.80 × 100 = 80%)
What is Percentage Calculator?
A percentage is a way of expressing a number as a fraction of 100. The word comes from Latin "per centum" meaning "by the hundred." We see percentages everywhere—shopping discounts, exam scores, interest rates, tip calculations, statistics, and food labels.
For example, according to Mars, Inc., 20% of M&M's in a bag should be orange. Whether it's a small 1.69 oz bag or a large 3 lb bag, regardless of the total number of candies, 20% (or 20 out of every 100) should be orange.
This calculator solves various percentage problems: find a percentage of any amount, determine what percentage one number is of another, calculate the whole from a known part and percentage, or add/subtract percentages.
Formula
Basic Percentage Formula:
(X / Y) × 100 = P%
Divide X by Y to get a decimal, multiply by 100 to get percentage
Finding P% of X:
Y = P% × X = (P / 100) × X
Example: 15% of $45 = 0.15 × 45 = $6.75
Finding What % Y is of X:
P% = (Y / X) × 100
Example: 12 of 40 eggs = (12/40) × 100 = 30%
Finding X when Y is P% of X:
X = Y / (P / 100)
Example: If 65 is 26% of X, then X = 65 / 0.26 = 250
Examples
Example 1: Calculate a 15% Tip on $45
Formula: Y = P% × X
Convert 15% to decimal: 15/100 = 0.15
Multiply: 0.15 × 45 = 6.75
15% of $45 = $6.75
Example 2: What Percent of 40 is 12?
Formula: P% = (Y / X) × 100
Divide: 12 / 40 = 0.3
Multiply by 100: 0.3 × 100 = 30%
12 is 30% of 40
Example 3: 9 is 60% of What Number?
Formula: X = Y / (P / 100)
Convert 60% to decimal: 60/100 = 0.6
Divide: 9 / 0.6 = 15
9 is 60% of 15
Example 4: $100 Plus 8% Tax
Formula: Result = X × (1 + P/100)
Calculate: $100 × (1 + 0.08)
= $100 × 1.08 = $108
$100 + 8% = $108