Percentage Calculator
Solve the three common percentage problems: percent of a number, what percent one number is of another, and percentage change.
15.00% of 200.00
30
Calculation15.00 ÷ 100 × 200.00
Result30
Remainder170
About the Percentage Calculator
Most percentage questions are one of three shapes. This calculator handles all three: finding a percentage of a number, expressing one number as a percentage of another, and measuring the percentage change between two values.
Formula
Percent of: X% of Y = (X ÷ 100) × Y. Is what percent: X ÷ Y × 100. Percentage change: (new − old) ÷ old × 100.
Frequently Asked Questions
Subtract the old value from the new one, divide by the old value, then multiply by 100. Going from 50 to 65 is (65 − 50) ÷ 50 × 100 = 30% increase.
Because each percentage applies to a different base. 100 rises by 50% to 150, then falls by 50% of 150 — which is 75 — leaving 75, not 100. Percentage changes do not cancel out.
A move from 10% to 12% is a rise of two percentage points, but a 20% increase in relative terms. News reports often confuse the two; the distinction matters for interest and polling figures.
Divide rather than subtract. To strip 20% tax from a total of 120, divide by 1.2 to get 100. Subtracting 20% of 120 would incorrectly give 96.
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