🔢 Math Tool

Percentage Calculator

Calculate any percentage instantly — find what % of a number is, calculate % change, reverse percentage, and more. 6 calculators in one tool.

What is X% of Y?

e.g. What is 20% of 500? → 100

What is

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Formula: (X ÷ 100) × Y

Quick:

X is what % of Y?

e.g. 25 is what % of 200? → 12.5%

is what % of

—

Formula: (X ÷ Y) × 100

Quick:

Percentage Change (Increase / Decrease)

e.g. Price went from ₹200 to ₹250 — what % increase?

From

→

—

Formula: ((New − Old) ÷ Old) × 100

Quick:

Add Percentage to a Number

e.g. ₹1000 + 18% GST = ₹1180

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Formula: Number × (1 + Percentage ÷ 100)

Quick:

Subtract Percentage (Discount Calculator)

e.g. ₹2000 − 30% discount = ₹1400

−

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Formula: Number × (1 − Percentage ÷ 100)

Quick:

Reverse Percentage (Find Original Value)

e.g. After 20% discount, price is ₹800 — what was original?

Final value

after

off

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Formula: Final Value ÷ (1 − Percentage ÷ 100)

Quick:

📋 Recent Calculations

How to calculate percentages

What is X% of Y? Divide X by 100, then multiply by Y. Example: 15% of 200 = (15÷100) × 200 = 30.

Percentage change: Subtract the old value from the new value, divide by the old value, multiply by 100. A positive result is an increase; negative is a decrease.

Common uses in India: GST calculation (add 5%, 12%, 18%, or 28%), discount calculation during sales, exam score percentages, EMI interest rates, salary hike percentages, and tipping at restaurants.

Tip: To quickly find 10% of any number, just move the decimal point one place to the left. 10% of 450 = 45. Then multiply for other percentages — 20% = double of 10%, 5% = half of 10%.