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Percentage Calculator

Calculate percentages, percentage change, and what percentage one number is of another with step-by-step solutions.

Related:
Triangle Calculator Quadratic Formula Pythagorean Theorem

Choose Calculation Type

Formula
Result = (Percentage ÷ 100) × Number
%
The total number or base value
💡 Tip: Results are calculated automatically as you type. Switch tabs to access different percentage calculations.

Result & Solution

Step-by-Step Solution

Enter values to see the step-by-step solution

Understanding Percentages

What is a Percentage?

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." It's denoted by the symbol % and is widely used in mathematics, statistics, and everyday life.

50% = 50/100 = 0.5
This means 50 out of every 100, or half

Three Main Types

  • Find percentage of number: What is 25% of 80? (Answer: 20)
  • Find what percentage: 15 is what percent of 60? (Answer: 25%)
  • Find percentage change: From 40 to 50? (Answer: +25% increase)

Converting Between Forms

Percentage
Decimal
Fraction
25%
0.25
1/4
50%
0.5
1/2
75%
0.75
3/4

Real-World Applications

  • Shopping: 20% discount on $100 = $20 off = $80 final price
  • Taxes: 8.5% sales tax on $50 = $4.25 tax
  • Tips: 18% tip on $45 meal = $8.10 tip
  • Finance: 5% annual interest on $1000 = $50 per year
  • Statistics: 85% test score means 85 out of 100 points

Step-by-Step Methods

Method 1: Percentage of a Number
1. Convert percentage to decimal: 25% → 0.25
2. Multiply: 0.25 × 80 = 20
3. Answer: 25% of 80 is 20
Method 2: What Percentage
1. Divide part by whole: 15 ÷ 60 = 0.25
2. Convert to percentage: 0.25 × 100 = 25%
3. Answer: 15 is 25% of 60
Method 3: Percentage Change
1. Find difference: 50 - 40 = 10
2. Divide by original: 10 ÷ 40 = 0.25
3. Convert to percentage: 0.25 × 100 = 25%
4. Answer: 25% increase

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