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Percentage Calculator

Free percentage calculator. Find X% of Y, work out what percent one number is of another, or calculate the percentage increase or decrease between two values.

About the Percentage Calculator

A percentage calculator answers the three everyday percentage questions: what X% of Y is, what percent X is of Y, and the percentage increase or decrease from X to Y (with the difference), updating as you type.

X% of Y = (X ÷ 100) × Y. That single formula answers the most common percentage question there is — what is 20% of 500? — and this calculator solves it instantly, along with the two other percentage questions people actually search for: what percent one number is of another, and how much a value has increased or decreased in percentage terms.

The three calculations use different arithmetic, so mixing them up is the usual source of error. "X% of Y" multiplies. "X is what percent of Y" divides X by Y and multiplies by 100 — useful for things like "I scored 42 out of 50, what percent is that?". "Percentage change from X to Y" takes (Y − X) ÷ X × 100 — the formula behind every price-increase, discount and salary-hike calculation, and the one people most often get backwards by dividing by the wrong number.

Pick the calculation you need from the dropdown, enter your two numbers, and the result updates immediately. For GST-specific percentage math (adding or removing tax from an amount), use the GST Calculator instead — it applies the same core arithmetic but with the CGST/SGST/IGST split built in.

Frequently asked questions

How do I calculate X% of Y?
Divide X by 100 and multiply by Y: X% of Y = (X ÷ 100) × Y. For example, 20% of 500 = (20 ÷ 100) × 500 = 100.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100: (part ÷ whole) × 100. For example, 42 out of 50 is (42 ÷ 50) × 100 = 84%.
Why did I get a negative result for percentage change?
A negative percentage change means Y is smaller than X — a decrease. This calculator shows the direction (increase or decrease) explicitly alongside the magnitude, so a negative sign is never the only signal.
What's the difference between percentage change and percentage points?
Percentage change is relative (a rate moving from 10% to 15% is a 50% increase, since 5 ÷ 10 × 100 = 50). Percentage points is the raw difference (that same move is "5 percentage points"). This calculator computes percentage change, not percentage points.

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