Fraction Calculator
Adds, subtracts, multiplies and divides fractions, reduces them and converts to and from decimals.
Adds, subtracts, multiplies and divides fractions exactly, and converts between fractions and decimals both ways. Every step uses arbitrary-precision integers, so adding thirds gives 1 rather than 0.9999999999999999.
Calculate
Write fractions as 3/4, mixed numbers as 1 1/2, decimals as 0.75, and repeating decimals as 0.(3).
Result
3/4 + 1/6 = 11/12
lowest terms
11/12
mixed number
11/12
decimal
0.91(6)
as a percentage
91.6667%
Every step is exact. The numerator and denominator are arbitrary-precision integers, so adding thirds gives 1 rather than 0.9999999999999999.
Decimal to fraction
A repeating decimal can be written with brackets: 0.(3) is exactly one third.
exact value
3/8
the decimal read literally
simplest nearby fraction
3/8
by continued fractions
How to use it
Write the two numbers
As fractions like 3/4, as mixed numbers like 1 1/2, as decimals like 0.75, or as repeating decimals with brackets: 0.(3) is exactly one third.
Pick the operation
The result comes back in lowest terms, as a mixed number, as a decimal and as a percentage at once.
Or convert a decimal
The second panel takes a decimal and gives both the literal fraction and the simplest nearby one.
Common questions
What fraction is 0.333333?
Two different questions hide in that. Read literally it is 333333/1000000. What people usually mean is the simplest fraction that rounds to it, which is 1/3 — found here by continued fractions, the same method that gives 355/113 for π.
How do I write a repeating decimal?
Put the repeating part in brackets: 0.(3) is a third, 0.1(6) is a sixth. Written that way it is converted exactly rather than approximated.
Is there a size limit?
Not a practical one. Numerator and denominator are arbitrary-precision integers, so a fraction with a fifty-digit denominator reduces exactly.
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