Fraction Calculator Widget

Add a fraction calculator to your maths pages. Students enter fractions such as 3/4 or mixed numbers such as 1 1/2 and get the answer in lowest terms, as a mixed number and as an exact decimal with the repeating digits marked.

Education & Math Calculator Runs in your browser Free · no ads

Customize your widget

Theme
Auto follows the visitor's light/dark setting.
Style
Attribution on your page
Optional and entirely your choice. The exact line is shown in the code below; it links to the tool with rel="nofollow".
More options
Starting values
Leave blank to use the widget's defaults. Visitors can still change every value.

Live preview

Exactly what your visitors will see

Embed code

<iframe src="https://a2z.tools/embed/w/fraction-calculator" title="Fraction Calculator by A2Z Tools" width="100%" height="470" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>

A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.

Works with

How it works

Each input is read as an exact fraction: mixed numbers become improper fractions, and terminating decimals such as 0.75 become 75/100. The arithmetic uses whole-number (BigInt) maths, so even very long numerators stay exact. The result is reduced with the greatest common divisor, the sign is moved to the numerator, and the working line shows the common denominator step. The decimal form is found by long division and marks a repeating block in brackets, for example 13/6 = 2.1(6).

Calculation method

  • a/b + c/d = (ad + bc) / bd; a/b - c/d = (ad - bc) / bd
  • a/b x c/d = ac / bd; a/b / c/d = a/b x d/c
  • Lowest terms: divide numerator and denominator by gcd(numerator, denominator)
  • Mixed number: whole part = numerator div denominator, remainder over the denominator

Worked examples

Adding a mixed number and a fraction

Inputs: 1 1/2 + 2/3

Result: 13/6 = 2 1/6 = 2.1(6)

Working shown: 3/2 + 2/3 = 9/6 + 4/6 = 13/6 in lowest terms.

Dividing by a decimal

Inputs: 3/4 / 0.125

Result: 6

0.125 is read as exactly 1/8, and 3/4 x 8 = 6.

The classic floating-point trap

Inputs: 0.1 + 0.2

Result: 3/10 = 0.3 exactly

The decimals become 1/10 and 1/5 before adding, so none of the binary rounding that makes ordinary software print 0.30000000000000004 can creep in.

Limitations

  • Two operands and one operation at a time; expressions such as 1/2 + 1/3 x 3/4 must be done step by step.
  • Repeating decimals cannot be typed as input: 0.333 is read as exactly 333/1000, so enter 1/3 instead.
  • No powers, roots or percentages of fractions, and inputs are limited to 70 characters each.

Where publishers use it

  • Primary and middle-school maths worksheets and lesson pages
  • Recipe sites where readers combine or scale fractional measures
  • Woodworking and DIY guides that work in fractions of an inch
  • Homeschooling resources that want the working, not just the answer

Questions

How do I enter a mixed number?

Type the whole number, a space and the fraction: 2 3/4. A negative mixed number is written -2 3/4 and means -(2 + 3/4).

Can I use decimals?

Yes, terminating decimals such as 0.75 or 1.2 are converted to exact fractions (3/4 and 6/5) before calculating.

What do the brackets in the decimal mean?

The digits in brackets repeat forever: 0.(142857) is 1/7 and 2.1(6) is 2.1666...

What happens with a zero denominator?

The widget refuses it with a message, because a fraction with denominator 0 is undefined. Dividing by a fraction equal to 0 is refused for the same reason.

Cite or recommend this tool

If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.

A2Z Tools Fraction Calculator
https://a2z.tools/embed/fraction-calculator

Related widgets

More Education & Math widgets →

Preview

CustomizeGet code