20% of 500 is 100. To calculate, multiply 500 by 0.20 (or divide by 5). Our percentage calculator handles this instantly.

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

Divide the part by the whole and multiply by 100. For example, 30 is what percent of 120? Answer: (30/120) × 100 = 25%.

Percentage Calculator

Q: How do I calculate percentage increase?

Percentage increase = ((New Value - Old Value) / Old Value) × 100. For example, if a price goes from $80 to $100, the percentage increase is ((100-80)/80) × 100 = 25%.

Solve any percentage problem instantly — find percentages, calculate changes, or determine what percent one number is of another.

What is X% of Y?

Percentage (%)

of this number

X is what percent of Y?

This number (X)

is what % of (Y)

Percentage increase or decrease from X to Y

Original value (X)

New value (Y)

How Percentage Calculators Work

Percentages are one of the most commonly used calculations in everyday American life — from calculating sales tax (typically 6–10% depending on state), restaurant tips (usually 15–20%), investment returns, salary increases, and discounts. Our calculator handles the three most common percentage problems.

Three Types of Percentage Problems

1. Finding X% of a Number

Formula: Result = (Percentage / 100) × Number
Example: What is 15% of $85 (restaurant tip)? Answer: 0.15 × 85 = $12.75

2. X Is What Percent of Y?

Formula: Percentage = (X / Y) × 100
Example: You scored 42 out of 50 on a test. What percentage did you get? Answer: (42/50) × 100 = 84%

3. Percentage Change

Formula: % Change = ((New − Old) / |Old|) × 100
Example: Your salary went from $65,000 to $72,000. That's a 10.77% raise.

Common Percentage Quick Reference

10% of any number = move decimal one place left

1% of any number = move decimal two places left

25% = divide by 4

50% = divide by 2

75% = divide by 4, multiply by 3

20% = divide by 5

Frequently Asked Questions

What is 20% of 500?

20% of 500 is 100. Calculation: 500 × 0.20 = 100. Or divide 500 by 5 = 100.

How do I calculate percentage increase?

Use: ((New − Old) / Old) × 100. If a price goes from $80 to $100: ((100−80)/80) × 100 = 25% increase.

How do I calculate a tip?

For a 20% tip on a $65 bill: 65 × 0.20 = $13 tip. Total: $78. Use our tip calculator for fast per-person splits.

How do I calculate sales tax?

Multiply the pre-tax price by the tax rate. Example: $50 item with 8% sales tax: 50 × 0.08 = $4 tax. Total = $54. US sales tax rates vary by state (0–10.25%).