➗ Free Percentage Calculator

How to Use This Calculator

Our free percentage calculator handles two common tasks: finding what percentage one number is of another, and calculating sale prices after discounts. Both are essential for everyday math.

For basic percentages: Enter the part (numerator) and the whole (denominator). For example, "What is 25% of 100?" — enter 25 and 100.

For discounts: Enter the original price and discount percentage. For example, a $100 item with 20% off.

Example Calculations

Example 1: What is 25% of 80?

• Method: 25 ÷ 100 × 80
• Or: 80 × 0.25
• Answer: 20

Example 2: $250 item with 35% discount

• Discount amount: $250 × 0.35 = $87.50
• Sale price: $250 - $87.50 = $162.50
• Or: $250 × 0.65 = $162.50

Example 3: What percentage of 200 is 50?

• Formula: (50 ÷ 200) × 100
• Answer: 25%

Why It Matters

Percentages are used constantly in daily life. Understanding them saves money and helps you make better decisions:

• Shopping - Calculate real sale prices, compare deals across different discount percentages
• Tipping - Figure out appropriate gratuity (15-20% is standard in the US)
• Finance - Understand interest rates, APR, credit card rates, investment returns
• Health - Read nutrition labels (percent daily value), track body fat percentage
• Business - Calculate profit margins, markups, growth rates, tax rates
• Taxes - Determine sales tax, income tax brackets, property tax rates

A study by MIT found that only 22% of adults can solve a basic percentage problem correctly. Knowing how to calculate percentages is a valuable skill that pays off financially.

Common Percentage Formulas

Task	Formula	Example
Find % of a number	Number × (Percentage ÷ 100)	15% of 200 = 30
Find what % one number is of another	(Part ÷ Whole) × 100	50 is 25% of 200
Calculate discount	Price × (1 - discount%)	$100 with 20% off = $80
Find percentage change	(New - Old) ÷ Old × 100	50 to 75 = +50%
Find original before % increase	New ÷ (1 + rate)	$120 after 20% increase = $100

Frequently Asked Questions

How do I calculate percentage of a number?

Multiply the number by the percentage as a decimal. Example: 20% of 150 = 150 × 0.20 = 30. Another method: divide by 100, then multiply: 150 ÷ 100 × 20 = 30. Both give the same answer.

What is the percentage formula?

Percentage = (Part ÷ Whole) × 100. For example, to find what percent of 50 is 10: (10 ÷ 50) × 100 = 20%. The "part" is what you're comparing, and the "whole" is the total.

How do I calculate a discount?

Subtract the discount percentage from 100%, then multiply by the original price. Example: $80 item with 25% off = $80 × 0.75 = $60. The discount amount would be $80 - $60 = $20.

How do I find the original number after a percentage increase?

Divide the new number by (1 + percentage as decimal). For $120 after 20% increase: $120 ÷ 1.20 = $100 original. This works because new = original × (1 + rate).

What's the difference between percent and percentage point?

This is a common source of confusion. If something goes from 10% to 15%, that's a 5 percentage point increase, but a 50% increase relative to the original. Percentage point is the absolute difference; percent change is relative.