Percentage Calculator
Three modes for all your percentage calculations.
Percentage Calculator — FAQ
How do I calculate X% of a number?
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Multiply the number by the percentage divided by 100. For example, 15% of 200 = 200 × (15/100) = 200 × 0.15 = 30. This is the most common percentage calculation used for tips, discounts, and tax amounts.
How do I find what percentage one number is of another?
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Divide the part by the whole and multiply by 100. For example, to find what percentage 45 is of 180: (45 ÷ 180) × 100 = 25%. This is useful for calculating grades, survey results, or share of a total.
How do I calculate percentage change (increase or decrease)?
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Percentage change = ((new value − old value) ÷ old value) × 100. A positive result is an increase; negative is a decrease. For example, a price rising from $80 to $100 is a 25% increase: ((100 − 80) ÷ 80) × 100 = 25%.
What is the difference between percentage points and percent?
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Percentage points measure absolute difference between two percentages, while percent measures relative change. If a tax rate rises from 20% to 25%, that is an increase of 5 percentage points, but it is a 25% relative increase (5 ÷ 20 × 100). These are often confused in media reporting.
How do I reverse a percentage (find the original value before a percentage was added)?
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Divide the final value by (1 + percentage/100). For example, if a price including 20% VAT is $120, the pre-tax price is $120 ÷ 1.20 = $100. This is called reverse percentage or finding the base value.