utility.diy

Fraction calculator

First fraction
Second fraction

Reduced result

...

Decimal: ...

How to calculate with fractions

Enter the numerator above the line and the denominator below it. The first fraction is the left-hand one in the mathematical expression. A denominator of 1 lets you use a whole number.

Adding and subtracting

Use a common denominator before combining the numerators. The calculator reduces the result automatically.

a/b + c/d = (a×d + c×b)/(b×d)

  1. Enter both fractions.
  2. Choose + or −.
  3. Read or copy the reduced exact result.

2/3 + 1/6 = 5/6. For subtraction, 2/3 − 1/6 = 1/2.

Multiplying and dividing

For multiplication, multiply the numerators and denominators. For division, multiply by the reciprocal of the second fraction.

a/b ÷ c/d = (a×d)/(b×c)

  1. Choose × or ÷.
  2. Use ± to change a fraction’s sign without a keyboard minus key.
  3. A denominator cannot be zero; division also requires a nonzero second fraction.

2/3 ÷ 4/5 = 5/6. A negative denominator is moved to the numerator in the reduced result.

Reduced, mixed and decimal forms

The exact numerator and denominator are divided by their greatest common divisor. Whole results omit /1. Improper non-integers also show a mixed number.

6/4 = 3/2 = 1 1/2 = 1.5

  1. Copy uses the exact reduced fraction, not the rounded decimal.
  2. A leading minus on a mixed number applies to the entire mixed number.
  3. Decimals show at most 12 places; ≈ means the decimal was rounded.

−7/3 = −2 1/3 ≈ −2.333333333333. The exact copied value remains −7/3.