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Percentage Calculator

Financial Calculators

Calculate percentage of a number, percentage change, what percent one number is of another, and percentage increase or decrease. Instant results with step-by-step formula explanations.

What is X% of Y?

What is X% of Y?

%

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Enter values to see the result instantly

Quick Examples

% of Number

20% of 150

= 30

% Change

80 → 100 (change)

= ▲ 25%

X is what %

50 is what % of 200?

= 25%

% Increase

Increase 200 by 15%

= 230

% Decrease

Decrease 200 by 15%

= 170

% Increase

VAT: 100 increase 20%

= 120

What Is a Percentage?

A percentage is a number or ratio expressed as a fraction of 100. The word "percent" comes from the Latin per centum, meaning "by the hundred." Percentages are used everywhere — from calculating a tip at a restaurant to understanding interest rates, exam scores, discounts, tax rates, and statistical data.

When you say "40%," you mean 40 out of every 100, or the fraction 40/100 = 0.40. This makes percentages a universal, intuitive way to compare proportions across different total sizes.

Key fact: 100% means the whole. More than 100% means more than the whole. Less than 0% is used to represent a deficit or negative change.

How to Calculate Percentages

Mode 1 — Percentage of a Number

What is 20% of 150?

Formula

Result = (X / 100) × Y

Example

(20 / 100) × 150 = 0.20 × 150 = 30

Mode 2 — Percentage Change

What is the % change from 80 to 100?

Formula

Change = ((B − A) / A) × 100

Example

((100 − 80) / 80) × 100 = (20 / 80) × 100 = 25%

Mode 3 — X is What % of Y?

50 is what percent of 200?

Formula

Result = (X / Y) × 100

Example

(50 / 200) × 100 = 0.25 × 100 = 25%

Mode 4 — Percentage Increase

Increase 200 by 15%

Formula

Result = X × (1 + Y/100)

Example

200 × (1 + 15/100) = 200 × 1.15 = 230

Mode 5 — Percentage Decrease

Decrease 200 by 15%

Formula

Result = X × (1 − Y/100)

Example

200 × (1 − 15/100) = 200 × 0.85 = 170

Percentage Increase vs Decrease

Percentage increase and decrease measure how much a value has changed relative to its original amount. They are not interchangeable — a 25% increase followed by a 25% decrease does not return to the original value.

TypeFormulaExample
IncreaseX × (1 + Y/100)200 × 1.15 = 230
DecreaseX × (1 − Y/100)200 × 0.85 = 170
% Change((B−A)/A) × 10080→100 = +25%
⚠️ Common mistake: +25% then −25% ≠ original. Starting at 100 → +25% = 125 → −25% = 93.75. Always calculate from the correct base value.

Real-Life Percentage Examples

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Shopping Discounts

A jacket costs $80. It is 30% off. Discount = 30% of 80 = $24. Final price = $56.

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Exam Scores

You scored 72 out of 90. 72 is what % of 90? = (72/90) × 100 = 80%.

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Investment Returns

Portfolio grew from $5,000 to $6,250. % increase = ((6250−5000)/5000) × 100 = 25%.

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Tax Calculation

Product costs $200 before 20% VAT. After tax = 200 × 1.20 = $240.

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Salary Raise

Earning $50,000/yr with a 7% raise. New salary = 50,000 × 1.07 = $53,500.

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Restaurant Tip

Bill is $65. 18% tip = 18% of 65 = $11.70. Total = $76.70.

Frequently Asked Questions

Explore This Tool in Context

Percentage Calculator is part of the Financial Calculators collection. If you want a broader view of similar workflows, open the Financial Calculators category page or browse all QuickTools categories.

Common next steps after this tool include Estate Tax Calculator, Social Security Calculator and Annuity Payout Calculator.

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