Percentage Calculator
Three percentage calculators in one: find X% of a number, find what percentage A is of B, or calculate percentage change from one value to another.
Calculate Percentages
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Details
Formulas
X% of Y = Y × X ÷ 100
X is ___% of Y = (X ÷ Y) × 100
% Change = (New − Old) ÷ Old × 100
X is ___% of Y = (X ÷ Y) × 100
% Change = (New − Old) ÷ Old × 100
Frequently Asked Questions
How do I calculate a percentage of a number?
Multiply by the percentage and divide by 100. Shortcut: move the decimal two places left. 15% of 80 = 0.15 × 80 = 12. 25% of any number = divide by 4. 10% = divide by 10. 5% = half of 10%.
How do I calculate percentage change?
% Change = (New − Old) ÷ Old × 100. Positive result = increase, negative = decrease. From $40 to $52: (52 − 40) ÷ 40 × 100 = 30% increase. From $52 back to $40: (40 − 52) ÷ 52 × 100 = −23.1% decrease — not 30%, because the base changed.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100. 45 out of 180 = 45 ÷ 180 × 100 = 25%. A score of 73 out of 85 = 73 ÷ 85 × 100 = 85.9%.