How do I calculate X% of Y?

Multiply Y by X/100. This tool does it automatically and shows the steps.

How do I calculate percentage change?

((New - Old) / Old) * 100. The tool shows whether it is an increase or decrease.

Does this tool save my numbers?

No. Calculations run in your browser and your inputs are not stored.

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✅ X% of Y 📈 % Change ➕ Increase ➖ Decrease 🔒 Private

Percentage Calculator

Q: What percent is A of B?

(A / B) * 100. Enter A and B to see the result instantly.

Calculate X% of Y, percentage change, increase/decrease, and “what percent is A of B” with clear steps. Perfect for shopping, business, school and finance.

Start Calculating →

Inputs

Pick a calculation type above. Enter values and get an instant result with a step-by-step breakdown.

Percent (X)

Number (Y)

Quick examples

20% of 150 = 30
15% off 200 = 170
Change from 80 to 100 = +25%

Result

—

Enter values and click Calculate.

Where this helps

Use percentage calculations for discounts, VAT, salary increments, grade calculations, profit margins, and quick comparisons. This calculator is designed to be fast and easy on mobile.

How to use the Percentage Calculator

1️⃣

Choose a mode

Pick X% of Y, % change, what percent, or increase/decrease.

2️⃣

Enter values

Use decimals if needed. The tool supports any numeric input.

3️⃣

Copy the result

Get a clean answer plus steps you can use in homework or reports.

Frequently Asked Questions

What is percentage change?▼

Percentage change tells you how much a value changed relative to the original value: ((new − old) / old) × 100.

Can I calculate increase and decrease?▼

Yes. Use the Increase/Decrease mode to apply a percent to a base value and get the new result.

Is this calculator private?▼

Yes. Calculations are performed in your browser and your inputs are not stored by Biberks Tools.

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