Enter the decimal you want as a fraction and press "Calculate" to see it in simplest form. A decimal greater than 1 is also shown as a mixed number.
Table of Contents
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What you can do on this page
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What is this calculation used for?
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How to Use
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Formula
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Symbols and terms
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Good to know before you start
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How to calculate it in Excel
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How to calculate it in Google Sheets
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How to calculate it in Python
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How to write it in LaTeX and other math languages (copy and paste)
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How to have ChatGPT do the calculation
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DataChef Features
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Related Features
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NumberChef Calculators List
What you can do on this page
- Enter a decimal such as 0.375, and you see it as a fraction in simplest form right away
- A decimal greater than 1, such as 1.375 → \(\dfrac{11}{8}\), is also shown as a mixed number (\(1\dfrac{3}{8}\))
- Negative decimals (for example, -2.25 → \(-\dfrac{9}{4}\)) and whole numbers are fine too. The steps "make the denominator a power of 10 → simplify with the greatest common factor" are shown as well
- A plain-language explanation of how to convert, and copy-and-paste formulas for Excel, Google Sheets and Python are all on this page
What is this calculation used for?
Recipes and measuring cups mostly use fractions such as "\(\dfrac{3}{4}\) cup". If a conversion chart or a digital scale gives you "0.75 cup", change it to \(0.75 = \dfrac{75}{100} = \dfrac{3}{4}\), and you can measure it with the \(\dfrac{3}{4}\) cup.
Being able to go back and forth between decimals and fractions makes baking from any recipe much easier.
Bolts, pipes and wrenches are sized in fractional inches such as \(\dfrac{3}{8}\) inch. If your measurement is in millimeters, first change it to decimal inches (\(9.525 \div 25.4 = 0.375\)), then turn that into a fraction, \(0.375 = \dfrac{375}{1000} = \dfrac{3}{8}\), and pick the \(\dfrac{3}{8}\) inch tool. A caliper reading of 0.375 inch works the same way.
Decimal to fraction is a calculation you really need when choosing parts at the hardware store or working with tools from another measuring system.
Hearing "the share in favor is 0.35" does not mean much to most people, but \(0.35 = \dfrac{35}{100} = \dfrac{7}{20}\) lets you say "7 out of 20 people are in favor".
In news, reports and presentations, turning a decimal proportion into a fraction such as "X out of Y" makes the same number much easier to understand.
Scales on models and maps are written as fractions or ratios such as \(\dfrac{1}{25}\) or 1:25. If a model is 0.04 times the size of the real car, change it to \(0.04 = \dfrac{4}{100} = \dfrac{1}{25}\), and it is a 1:25 scale model.
For models, maps and plans, a fraction shows "what fraction of the real size" much more directly than a decimal, so this conversion is used all the time.
In written music, a whole note counts as 1, and the other notes are named as fractions of it: half note = \(\dfrac{1}{2}\), quarter note = \(\dfrac{1}{4}\), eighth note = \(\dfrac{1}{8}\). If music software shows a note length of "0.125" with a whole note as 1, then \(0.125 = \dfrac{125}{1000} = \dfrac{1}{8}\), so it is an eighth note (some software measures length in beats or other units instead).
Turning decimals into fractions lets you move between the numbers you type in and the language of written music.
Formula
Symbols and terms
Symbols
| \(x\) | x | The original decimal you want as a fraction. (Examples - 0.375, 1.375, -2.25) |
| \(n\) | lowercase n | The number of decimal places (how many digits are to the right of the decimal point). (Example - for 0.375, \(n = 3\)) |
| \(10^{n}\) | 10 to the n | 10 multiplied by itself \(n\) times (10, 100, 1000, …). The small \(n\) at the upper right is the exponent, meaning "multiply \(n\) times", and it equals the number of zeros after the 1. On this page it goes in the denominator of the fraction. |
| \(a\) | a | The whole number you get by removing the decimal point from the original decimal. It goes in the numerator. (Example - 375 for 0.375) |
| \(g\) | g | The greatest common factor of the numerator and denominator. To simplify, divide both by this number. (Example - 125 for 375 and 1000) |
| \(\gcd(a,\ 10^{n})\) | GCD of a and 10 to the n | The notation for "the greatest common factor of \(a\) and \(10^{n}\)". GCD stands for greatest common divisor, another name for the greatest common factor. |
| \(N\) | capital N | The new numerator after simplifying. (Example - the 3 in \(\dfrac{3}{8}\), the simplified form of \(\dfrac{375}{1000}\)) |
| \(D\) | capital D | The new denominator after simplifying. (Example - the 8 in \(\dfrac{3}{8}\), the simplified form of \(\dfrac{375}{1000}\)) |
| \(q\) | q | The quotient when you divide the numerator by the denominator. It becomes the whole-number part of the mixed number. (From the first letter of "quotient") |
| \(r\) | r | The remainder when you divide the numerator by the denominator. It becomes the numerator of the fraction part of the mixed number. (From the first letter of "remainder") |
Terms
| terminating decimal | A decimal whose digits come to an end, such as 0.375. This calculator converts terminating decimals. |
| repeating decimal | A decimal in which the same block of digits repeats forever, such as 0.333…. The power-of-10 method on this page cannot convert it. It needs a different method (one that uses an equation), so this calculator does not handle it. |
| power of 10 | A number made by multiplying 10 by itself some number of times, such as 10, 100, 1000, …. The \(n\)th place after the decimal point is the "1 over \(10^{n}\)" place, so a power of 10 becomes the denominator when you turn a decimal into a fraction. |
| simplify | To divide the numerator and denominator of a fraction by a number that divides both (a common factor), making the fraction simpler. The value does not change. Also called reducing. |
| simplest form | A fraction that cannot be simplified any further (also called lowest terms). The greatest common factor of its numerator and denominator is 1. When a test says "write your answer in simplest form", this is the form it means. |
| greatest common factor (GCF) | The largest of the numbers that divide both of two numbers (their common factors). It is also called the greatest common divisor (GCD). |
| improper fraction | A fraction whose numerator is greater than or equal to its denominator, such as \(\dfrac{11}{8}\). A fraction worth 1 or more has this form. |
| mixed number | A number written as a whole-number part followed by a fraction part, such as \(1\dfrac{3}{8}\) ("one and three eighths"). It shows the same value as an improper fraction in a form where the size is easy to see. |
Good to know before you start
Here is what helps you use the calculation on this page with real understanding, not just by pressing the button.
If you get stuck, going back over these topics is the quickest way forward.
| Decimal place value (Grades 4–5) |
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| What a fraction means (Grade 3) |
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| Simplifying fractions and common factors (Grades 4–6) |
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| Mixed numbers, improper fractions and remainders (Grades 4–5) |
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| Terminating and repeating decimals (Grades 7–8) |
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How to calculate it in Excel
| Decimal to convert x | 1.375 |
| Decimal places n | 3 |
| Numerator a (no decimal point) | =B1*10^B2 |
| Denominator (power of 10) | =10^B2 |
| Numerator a | 1375 |
| Denominator (power of 10) | 1000 |
| Greatest common factor g | =GCD(B1,B2) |
| New numerator N | =B1/B3 |
| New denominator D | =B2/B3 |
| Numerator of the improper fraction N | 11 |
| Denominator D | 8 |
| Whole-number part (quotient q) | =QUOTIENT(B1,B2) |
| Numerator of the fraction part (remainder r) | =MOD(B1,B2) |
"^" is a power (10^3 is 1000). GCD finds the greatest common factor, QUOTIENT the quotient (whole-number part), and MOD the remainder.
For 1.375, for example, the first table gives the numerator 1375 and denominator 1000 (B3 and B4), the second table simplifies with the GCF 125 to \(\dfrac{11}{8}\) (B4 and B5), and the third table gives the mixed number \(1\dfrac{3}{8}\) (B3 and B4). For a negative decimal, calculate with the value without its minus sign and add the sign at the end.
How to calculate it in Google Sheets
| Decimal to convert x | 1.375 |
| Decimal places n | 3 |
| Numerator a (no decimal point) | =B1*10^B2 |
| Denominator (power of 10) | =10^B2 |
| Numerator a | 1375 |
| Denominator (power of 10) | 1000 |
| Greatest common factor g | =GCD(B1,B2) |
| New numerator N | =B1/B3 |
| New denominator D | =B2/B3 |
| Numerator of the improper fraction N | 11 |
| Denominator D | 8 |
| Whole-number part (quotient q) | =QUOTIENT(B1,B2) |
| Numerator of the fraction part (remainder r) | =MOD(B1,B2) |
How to calculate it in Python
from fractions import Fraction
decimal_text = "1.375" # the decimal to convert (write it as a string to avoid rounding errors)
fraction_value = Fraction(decimal_text) # simplifying is done automatically
print(f"Fraction: {fraction_value}") # 11/8
# Change the improper fraction to a mixed number (whole-number part and remainder)
numerator = abs(fraction_value.numerator)
denominator = fraction_value.denominator
whole_part, remainder = divmod(numerator, denominator)
sign = "-" if fraction_value < 0 else ""
if whole_part > 0 and remainder > 0:
print(f"Mixed number: {sign}{whole_part} {remainder}/{denominator}")
How to write it in LaTeX and other math languages (copy and paste)
x = a ÷ 10ⁿ
x = \dfrac{a}{10^{n}}
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<mrow>
<mi>x</mi>
<mo>=</mo>
<mfrac>
<mi>a</mi>
<msup><mn>10</mn><mi>n</mi></msup>
</mfrac>
</mrow>
</math>
x = a / 10^n
a/10^n
x := a/10^n;
x = a/10^n;
x = a/10^n
a/10ⁿ = (a ÷ g)/(10ⁿ ÷ g)
\dfrac{a}{10^{n}} = \dfrac{a \div g}{10^{n} \div g}, \quad g = \gcd(a,\ 10^{n})
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<mrow>
<mfrac>
<mi>a</mi>
<msup><mn>10</mn><mi>n</mi></msup>
</mfrac>
<mo>=</mo>
<mfrac>
<mrow><mi>a</mi><mo>÷</mo><mi>g</mi></mrow>
<mrow><msup><mn>10</mn><mi>n</mi></msup><mo>÷</mo><mi>g</mi></mrow>
</mfrac>
</mrow>
</math>
a/10^n = (a -: g)/(10^n -: g)
(a/g)/(10^n/g)
(a/g)/(10^n/g);
N = a/g; D = 10^n/g;
a/10^n = (a÷g)/(10^n÷g)
N = q × D + r
N = q \times D + r
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<mrow>
<mi>N</mi>
<mo>=</mo>
<mi>q</mi>
<mo>×</mo>
<mi>D</mi>
<mo>+</mo>
<mi>r</mi>
</mrow>
</math>
N = q xx D + r
q*d + r (* D (the derivative operator) is reserved in Mathematica, so a lowercase d is used *)
N := q*d + r; # D (the derivative operator) is reserved in Maple, so a lowercase d is used
N = q*D + r;
N = q × D + r
How to have ChatGPT do the calculation
You are a math calculation assistant. Do the following calculation by actually running Python code, and base your answer only on the numbers from the execution result (do not answer by mental math or guessing). Convert the decimal 1.375 to a fraction. 1. The fraction in simplest form 2. The same value as a mixed number (with a whole-number part) 3. The steps (the fraction with a power-of-10 denominator, and the greatest common factor used to simplify it) Use Python's fractions module (pass the value to Fraction as a string), and show the formulas you used and the execution result.
How to Use
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1Enter your numbersType the numbers you want to calculate with into the input fields
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2CalculatePress the "Calculate" button
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3Check the resultThe result appears on the spot. The same page also explains the idea behind the calculation and the formula
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