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Tool Percentage Calculator

Choose a mode below, enter your numbers, and get instant results with a step-by-step explanation. Handles percentages, percentage change, discounts, and reverse calculations.

Find what a percentage of a number equals. Example: What is 20% of 150?

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Enter your numbers and press Calculate to see the result.

Formulas All Percentage Formulas in One Place

These four formulas cover almost every percentage problem you'll encounter.

1. What is X% of Y?

Result = (X ÷ 100) × Y

2. X is what % of Y?

Percentage = (X ÷ Y) × 100

3. Percentage Increase / Decrease

% Change = ((New − Old) ÷ Old) × 100
Positive result = increase, Negative result = decrease

4. Discount / % Off Price

Savings = (Discount% ÷ 100) × Original Price
Final Price = Original Price − Savings
Memory trick: The word percent literally means "per hundred" (per centum in Latin). So X% just means X/100. Any percentage formula is just a fraction problem in disguise.

Reference Common Percentage Values

Quick reference for the most-used percentages of common numbers.

Percentage of 50 of 100 of 200 of 500
5% 2.5 5 10 25
10% 5 10 20 50
15% 7.5 15 30 75
20% 10 20 40 100
25% 12.5 25 50 125
30% 15 30 60 150
50% 25 50 100 250
75% 37.5 75 150 375

FAQ Frequently Asked Questions

What is 20% of 150?

20% of 150 is 30. Calculation: (20 ÷ 100) × 150 = 0.2 × 150 = 30.

How do I find what percentage one number is of another?

Divide the part by the whole, then multiply by 100: (Part ÷ Whole) × 100. For example, if 30 is the part and 150 is the whole, then (30 ÷ 150) × 100 = 20%.

How do I calculate a percentage increase?

Use the formula: ((New − Old) ÷ Old) × 100. For example, if a price goes from $80 to $100, the increase is (20 ÷ 80) × 100 = 25%.

How do I calculate a percentage decrease?

Use the same formula as increase but the result will be negative: ((New − Old) ÷ Old) × 100. For example, if a price drops from $100 to $80, the decrease is (−20 ÷ 100) × 100 = −20%, i.e., a 20% decrease.

What is a 25% discount on a $80 item?

25% of 80 = 20. So you save $20 and pay $60 after the discount.

How do I calculate a tip?

Use the "X% of Y" mode: for a 15% tip on a $60 bill, calculate 15% of 60 = $9. Total to pay = $69.

What's the difference between percent and percentage point?

A percent is a relative change (e.g., a rate going from 5% to 10% is a 100% increase). A percentage point is an absolute change in a percentage value (from 5% to 10% is a 5 percentage-point increase).

Can percentages be greater than 100?

Yes! A 150% value means 1.5 times the original. This is common in growth metrics, e.g., a stock going up 200% means it tripled.