Percentage Calculator

Calculate percentages, percentage changes, discounts, and more.

Only numbers and decimal points are allowed in input fields
Percentage of a Number
What is X% of Y?
% of
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What Percent
X is what % of Y?
is what % of
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Percentage Change
% increase or decrease
Fromto
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Discount Calculator
Discounted price and savings
$with% off
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How to Use the All-in-One Percentage Calculator

Whether you are calculating shopping discounts, solving school math problems, or evaluating financial profit margins, this tool handles all four essential percentage calculations in one place.

1. Percentage of a Number (What is X% of Y?)

Use this to find a specific share or part of a whole amount. Common for tips, commissions, and tax calculations.

Formula: (X ÷ 100) × Y

Example: What is 15% of $80?
(15 ÷ 100) × 80 = $12

2. What Percent (X is What % of Y?)

Determines what fraction one number represents compared to another. Ideal for test scores and goal tracking.

Formula: (X ÷ Y) × 100

Example: You scored 45 marks out of 60.
(45 ÷ 60) × 100 = 75%

3. Percentage Change (Increase or Decrease)

Calculates the rate of change between an initial value and a new value. Perfect for inflation, sales growth, or weight tracking.

Formula: [(New Value − Old Value) ÷ Old Value] × 100

Example: A price went from $50 to $70.
[(70 − 50) ÷ 50] × 100 = +40% increase

4. Discount & Savings Calculator

Instantly calculates your total savings and final discounted price during retail shopping and clearance sales.

Formula: Final Price = Original Price − [Original × (Discount % ÷ 100)]

Example: A jacket costs $120 with 25% off.
Savings: $30 | Final Price: $90

Quick Mental Math Tricks for Percentages

  • Reversible Percentages: X% of Y is always equal to Y% of X. Finding 8% of 50 is tricky, but 50% of 8 is simply 4.
  • The 10% Rule: To find 10% of any number, move the decimal point one place to the left (e.g., 10% of 240 is 24). For 20%, simply double that number (48).
  • The 1% Rule: Move the decimal point two places to the left to find 1% (e.g., 1% of 350 is 3.5).

Frequently Asked Questions

Common questions about percentage calculations and formulas.

Multiply the original price by the discount rate and divide by 100 to determine how much you save. Then subtract your savings from the original price. For example, on a $50 shirt with a 20% discount: $50 × (20 ÷ 100) = $10 savings, making your final checkout price $40.

Subtract the initial value from the new value, divide by the initial value, and multiply by 100. If the resulting number is positive, it is a percentage increase; if negative, it is a percentage decrease.

Percentage comes from the Latin phrase per centum, meaning "by the hundred." It represents a number or ratio expressed as a fraction of 100, symbolized by the % sign.

Yes. Any value that is more than double the original reference amount exceeds 100%. For instance, if an investment grows from $100 to $250, it represents a 150% increase, or 250% of the starting amount.