Add, subtract, multiply and divide fractions and mixed numbers and see every step, or convert between fractions, decimals and percentages. Answers come out simplified, as a mixed number, a decimal and a percentage.
For a mixed number like 2 3/5, type the whole part (2) in the small box.
34+16=1112
Answer
11/12
Decimal
0.91(6)
Percentage
91.6667%
How it's worked out
The lowest common denominator of 4 and 6 is 12.
3/4 = (3 × 3) / (4 × 3) = 9/12
1/6 = (1 × 2) / (6 × 2) = 2/12
9/12 + 2/12 = 11/12
Exact arithmetic with whole numbers, so even long numerators keep every digit. Repeating decimal digits are shown in brackets: 1/3 = 0.(3).
How to use the fraction calculator
Enter the first fraction: the numerator on top and the denominator below, with a whole number in front for a mixed number.
Choose +, −, × or ÷ and enter the second fraction.
Read the answer in its simplest form, as a mixed number, a decimal and a percentage, with the working step by step.
To convert or simplify one value, choose "Convert or simplify" and type a fraction (3/8), a mixed number (1 1/2), a decimal (0.375) or a percentage (37.5%).
Fraction rules
Add or subtract:a/b + c/d = (a × d + c × b) / (b × d), simplest with the lowest common denominator.
Multiply:a/b × c/d = (a × c) / (b × d)
Divide:a/b ÷ c/d = a/b × d/c
Simplify: divide the top and bottom by their greatest common divisor.
Common fractions as decimals and percentages
Digits in brackets repeat forever.
Fraction
Decimal
Percentage
1/2
0.5
50%
1/3
0.(3)
33.3333%
2/3
0.(6)
66.6667%
1/4
0.25
25%
3/4
0.75
75%
1/5
0.2
20%
1/6
0.1(6)
16.6667%
1/8
0.125
12.5%
3/8
0.375
37.5%
5/8
0.625
62.5%
7/8
0.875
87.5%
1/10
0.1
10%
Working with percentages? The percentage calculator finds a percent of a number and percentage changes, and the scientific calculator handles powers, roots and trigonometry.
Frequently asked questions
How do you add fractions with different denominators?
Rewrite both over their lowest common denominator, then add the numerators. For 3/4 + 1/6 the lowest common denominator is 12, so 3/4 = 9/12 and 1/6 = 2/12, and 9/12 + 2/12 = 11/12. Subtracting works the same way: 3/4 − 1/6 = 9/12 − 2/12 = 7/12.
How do you multiply and divide fractions?
To multiply, multiply the numerators and the denominators: 3/4 × 1/6 = 3/24 = 1/8. To divide, flip the second fraction and multiply: 3/4 ÷ 1/6 = 3/4 × 6/1 = 18/4 = 9/2, or 4 1/2 as a mixed number.
How do I convert a fraction to a decimal or a percentage?
Divide the numerator by the denominator, then multiply by 100 for a percentage: 3/8 = 0.375 = 37.5%. Some fractions repeat forever: 1/3 = 0.333… (shown as 0.(3)) and 1/7 = 0.(142857), where the digits in brackets repeat.
How do I turn a decimal into a fraction?
Write the digits over 10, 100, 1,000… (one zero per decimal place), then simplify: 0.375 = 375/1000 = 3/8. A rounded decimal such as 0.3333 is exactly 3333/10000, but it's almost certainly 1/3; the calculator points that out. A percentage works the same way over 100: 37.5% = 37.5/100 = 3/8.
How do you simplify a fraction?
Divide the top and bottom by their greatest common divisor. For 18/24 that's 6, so 18/24 = 3/4. When the greatest common divisor is 1 the fraction is already in its lowest terms. Type a fraction in the Convert box to simplify it.
How do I calculate with mixed numbers?
Turn each mixed number into an improper fraction first: 2 3/5 = (2 × 5 + 3)/5 = 13/5 and 1 1/2 = 3/2. Then work as usual: 13/5 + 3/2 = 26/10 + 15/10 = 41/10 = 4 1/10. In the calculator, type the whole number in the small box in front of the fraction.
