Mathematics calculators
Everyday arithmetic and statistics, done exactly. Fractions stay as fractions, decimals do not pick up rounding noise, and each tool explains the method behind the answer.
- Percentage CalculatorA percentage is a number expressed as a fraction of 100. This calculator answers the three everyday questions: what is X% of Y, X is what percent of Y, and X is Y% of what.
- Percentage Change CalculatorPercentage change measures how much a value has grown or shrunk relative to where it started. It is always calculated against the original value.
- Average CalculatorThe everyday “average” is the arithmetic mean: add the numbers and divide by how many there are. The median and mode describe the middle and the most common value.
- Ratio CalculatorA ratio compares two quantities. Simplifying divides both sides by their greatest common divisor; scaling keeps the same proportion with different numbers.
- Fraction CalculatorThis calculator works with exact whole-number fractions, so 1/3 stays 1/3 instead of becoming 0.333…, and every answer is reduced to lowest terms.
- Standard Deviation CalculatorStandard deviation measures how spread out numbers are around their mean. A small value means the data clusters tightly; a large value means it is widely spread.