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Find a percentage of a number, work out what percent one number is of another, or calculate a percentage increase or decrease — instantly.
A percentage is a way of expressing a number as a fraction of 100. The word comes from the Latin per centum, meaning "by the hundred." When you say something is "20%," you mean 20 out of every 100 — the same as the fraction 20/100 or the decimal 0.2.
Percentages let us compare quantities of different sizes on a common scale. Whether you're calculating a discount at checkout, working out exam results, tracking investment growth, or reading a nutrition label, percentages turn raw numbers into something easy to compare and understand.
The core percentage formula is the same one this calculator uses behind the scenes. There are three common versions, depending on what you already know and what you're solving for.
Divide the part by the whole, then multiply by 100. For example, to find what percentage 30 is of 200: (30 ÷ 200) × 100 = 15%.
Multiply the number by the percentage, then divide by 100. For example, 20% of 150 is (150 × 20) ÷ 100 = 30.
Subtract the original value from the new value, divide by the original value, then multiply by 100. A positive result is a percentage increase; a negative result is a percentage decrease.
A percentage point is the arithmetic difference between two percentages. If a rate moves from 20% to 25%, that's a rise of 5 percentage points — but a 25% relative increase in the rate itself.