About Subtract Fractions Calculator
This calculator subtracts fractions with the same or different denominators. Enter 3/4 and 1/6 and it finds the common denominator 12, rewrites them as 9/12 and 2/12, and returns 7/12. It is free, needs no sign-up and runs in your browser, so nothing you enter is uploaded.
Subtraction follows the same plan as addition: common denominator first, then subtract the numerators. The order matters. If the second fraction is larger, the answer is negative, and the calculator keeps the sign: 1/4 − 2/3 is 3/12 − 8/12 = −5/12.
A negative fraction is written with the minus sign on the front, and its decimal is negative too: −5/12 is −0.41(6). Mixed numbers can be entered directly, so there is no need to convert them yourself.
How to use Subtract Fractions Calculator
- Choose a mode: Calculate, Simplify, Compare, Decimal to fraction, Fraction to decimal, Improper to mixed or Fraction to percent.
- In Calculate mode type one expression with +, −, × and ÷ and as many brackets as you need. Mixed numbers are written with a space, such as 2 1/2, and repeating decimals as 0.(3).
- Read the result as a reduced fraction, a mixed number, a decimal and a percent.
- The tool opens on a worked example. Read the steps to see each operation done in the order brackets and precedence require.
- For an improper result, a second panel shows how to convert it to a mixed number.
Features
- Exact rational arithmetic with no floating-point error, using whole-number numerators and denominators of any size.
- Expressions with any number of terms, brackets, mixed numbers, negative fractions, decimals and repeating decimals such as 0.(3) and 0.1(6).
- Results shown as a fraction, a mixed number, a decimal and a percent together.
- Repeating decimals shown exactly with a bar over the repeating block, for example 1/7 = 0.142857 repeating, and accepted as input.
- Step-by-step working in typeset math: converting each number to a fraction, then each operation in order with its least common denominator or reciprocal and the simplification.
- Compare mode that shows both fractions over a common denominator and as decimals.
- Decimal to fraction, fraction to decimal, improper to mixed number and fraction to percent conversions.
- Clear messages for a zero denominator or division by zero.
Subtracting fractions
Over the least common denominator L, subtract the numerators and simplify.
a/b − c/d = (a × (L ÷ b) − c × (L ÷ d)) / L, where L = lcm(b, d)Worked examples
3/4 − 1/6 gives 7/12
LCD(4, 6) = 12. 9/12 − 2/12 = 7/12.
1/4 − 2/3 gives −5/12
LCD(4, 3) = 12. 3/12 − 8/12 = −5/12, which is about −0.4167.
Privacy: how it works
- The fractions you enter are processed by code running in your browser tab. Nothing is sent to Ulkaa or anyone else, and there is nothing to sign in to.
Tips
- Write a mixed number with a single space between the whole part and the fraction, as in 1 3/4.
- A decimal such as 0.75 is accepted as an input anywhere a fraction is.
- If you want a rounded decimal for a calculation by hand, read it from the repeating form and cut it where you need.
- To check an answer, the Compare mode shows two fractions over one denominator, which is the same test teachers use.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial and no credit card. Ulkaa Tool does the work with your own device, so there is no server bill to pass on to you.
Do I need an account?
No. There is no sign-up and no login. Open the page and use it. An Ulkaa account is not needed for anything on this tool.
Does it run in my browser?
Yes. Your fractions are processed by code running in your browser tab, on your own device.
Is my data uploaded?
No. Your fractions are never sent to Ulkaa or to anyone else. You can check this yourself by watching the Network tab in your browser developer tools while you use the tool.
How do I subtract fractions with different denominators?
Rewrite both over a common denominator, subtract the second numerator from the first, keep the denominator and simplify.
What if the answer is negative?
That happens when the second fraction is larger. Keep the negative sign: 1/4 − 2/3 = −5/12.
More Fraction Calculator pages
- Fraction CalculatorAdd, subtract, multiply, divide, simplify, compare and convert fractions, with every step shown.
- Add Fractions CalculatorAdd two fractions and see the common denominator, the sum and the simplified answer.
- Multiply Fractions CalculatorMultiply two fractions or mixed numbers and simplify the product.
- Divide Fractions CalculatorDivide fractions and mixed numbers, with the reciprocal step shown.
- Simplify Fractions CalculatorReduce a fraction to lowest terms and see the GCD used.
- Mixed Number CalculatorCalculate with mixed numbers such as 2 1/2 and see the answer as a mixed number.
- Decimal to Fraction CalculatorTurn a decimal into an exact, simplified fraction.
- Fraction to Decimal CalculatorDivide a fraction out and see ending and repeating decimals exactly.
- Compare Fractions CalculatorCheck which fraction is bigger and see the proof.
- Improper Fraction to Mixed NumberSplit an improper fraction into a whole number and a proper fraction.
- Fraction to Percentage CalculatorConvert any fraction or mixed number to an exact percentage.