Percentage vs percentage points?

Going from 10% to 12% is a 2 percentage-point rise but a 20% relative increase — our ‘% change’ mode gives the relative figure.

What formula does the Percentage Calculator use?

It calculates using X% of Y = X/100 · Y; Change = (new − old)/old · 100. The guide above walks through what each part means with a worked example.

How accurate is the Percentage Calculator?

The answer is mathematically exact for the numbers you enter — the calculator applies the standard formula precisely and shows the full working.

Is this calculator free to use?

Yes — every GKCalculators calculator is 100% free with no sign-up required. Create a free account only if you want to save your calculation history across devices.

All calculations run instantly in your browser. Nothing is sent anywhere unless you tap ‘Explain my results’ (AI) or ‘Save’ while signed in.

Can I share my result?

Yes. Tap Share and we copy a link with your exact inputs baked in, so anyone who opens it sees the same result.

Percentage Calculator

Percent of, percent change, and add/subtract a percentage instantly.

Compare

Percentage (%)

Of value

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15% of 200

AI Breakdown & Smart Takeaway

Plain-English insight on your numbers

Get a personalized explanation of what these results mean — and how to improve them.

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How the Percentage Calculator works

The GKCalculators Percentage Calculator handles three essential percent operations in one place: finding what percent one number is of another, calculating percent change between two values, and adding or subtracting a percentage from a number. It's ideal for students, shoppers, business analysts, and anyone who needs fast, accurate percentage math without rearranging formulas by hand.

Three modes cover the everyday questions: a percentage of a number, what percent one number is of another, and percentage change between two numbers.

Formula

X% of Y = X/100 · Y;  Change = (new − old)/old · 100

Pro tips

Use ‘% change’ for price rises, discounts, tips and growth rates.

Key terms

Base Value: — The original or reference number from which a percentage is calculated; in a percent-change problem this is always the starting (old) value.
Percent Change: — The relative difference between two values expressed as a percentage of the original value, showing growth (positive) or decline (negative).
Percentage Point: — An absolute arithmetic difference between two percentage figures, distinct from the relative percent change between them.
Discount: — A percentage subtracted from an original price to reduce the amount a buyer pays, calculated by multiplying the price by the discount rate.
Tip: — A percentage added to a bill — typically 15–25% in the US — to compensate service staff, computed by multiplying the subtotal by the chosen tip rate.
Multiplier: — The decimal factor (1 ± rate/100) applied to a base value to produce the result after adding or subtracting a percentage in a single arithmetic step.