How this calculator works
Divide the numerator by the denominator to get the decimal ratio. A percentage expresses that same ratio per hundred. Numerators larger than their denominators give percentages above 100%, and a single negative sign makes the result negative. The calculation uses finite floating-point values and rounds only the displayed result.
Formula
Decimal ratio = numerator / denominator. Percentage number = 100 × numerator / denominator.
Worked example
3/8 = 0.375, so it is 37.5%. For -7/2 the decimal is -3.5 and the percentage is -350%.
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Frequently asked questions
Must the fraction be simplified?
No. Equivalent fractions give the same percentage because their numerator-to-denominator ratio is unchanged.
Can a fraction be more than 100%?
Yes. An improper positive fraction such as 7/4 equals 175%.
Why reject a zero denominator?
Division by zero is undefined. A zero numerator with a non-zero denominator is valid and equals 0%.