To enter a fraction in Excel without it turning into a date, type a zero, a space and the fraction. So 0 1/2 stores 0.5. If you type 1/2 alone, Excel may read it as a date. After that, the cell format decides whether you see the decimal or the fraction.
This guide is about spreadsheets. If you need the fraction inside a text document, see how to type fractions in Word and Google Docs, where the problem is a different one.
| What you type | What Excel stores | With format # ?/? |
|---|---|---|
0 2/5 | 0.4 | 2/5 |
2 3/4 | 2.75 | 2 3/4 |
0.625 | 0.625 | 5/8 |
1/2 | a date (January 2) if the cell has no fraction format | 1/2, and it stores 0.5 if the format was applied before typing |
The table sums up the rule. The whole number, even if it is zero, makes what follows part of a number. The format only changes how that number is drawn.
Typing the fraction so Excel stores it as a number
Type the leading zero whenever the fraction is less than 1. Microsoft explains it with another example: to enter 9/12 you type 0 9/12, and the zero disappears when you press Enter. With a mixed number you do not need the zero, because there is already a whole number in front: 2 3/4 stores 2.75.
To check what is stored, type =A1*4 in another cell. If A1 holds 0 3/4, the result is 3. If Excel returns an error or a large number, the cell holds a date or text.
Choosing the fraction format
The format is chosen on the Home tab, in the Number group, with the Fraction category of the Format Cells box. Microsoft’s help lists types such as single-digit, double-digit and triple-digit fractions, which set how many digits the denominator may have, and fractions as halves, quarters, eighths, sixteenths, tenths or hundredths, which fix the denominator. If you need another one, like 32, enter a custom format: in Type, # ?/32. With 0.4375 the cell shows 14/32 and still stores 0.4375.
| Excel type | Value 0.375 | Value 0.3 | Value 0.8 |
|---|---|---|---|
Single-digit fraction, code # ?/? | 3/8 | 2/7 | 4/5 |
Double-digit fraction, code # ??/?? | 3/8 | 3/10 | 4/5 |
| Fraction as sixteenths | 6/16 | 5/16 | 13/16 |
With one digit, 0.3 shows as 2/7 and not as 3/10, because 10 has two digits. The fraction shown is the closest one that fits: 2/7 is 1/70 away from 0.3 and 1/3 is 1/30 away, so 2/7 wins. With two digits, 3/10 fits, and it is exact.
Sixteenths are not reduced, so 0.375 appears as 6/16, not 3/8. This is useful for measurements in inches, where 0.4375 shows as 7/16. To convert that measurement to millimeters, use the fractional inches to mm tool.
What you see is not what is stored
The fraction format draws the number and does not change it. If a cell stores 0.333 and you see it as 1/3, the formula =A1*3 returns 0.999, not 1. The difference between 1/3 and 0.333 is 1/3000, about 0.000333.
That is why a fraction that looks exact may not be. When you need the exact value, write it as a fraction or convert it first with decimal to fraction, which returns the reduced fraction. To see the decimal of a fraction, use fraction to decimal, which marks the repeating part if there is one.
A spreadsheet also stores decimals in binary, and 0.1 or 0.3 have no finite binary form. That small remainder explains why 0.1 + 0.2 does not give 0.3 on a computer.
Simplifying a fraction with GCD
Excel does not reduce a fraction written with the numerator and denominator in separate cells, but it has the GCD function, which calculates the greatest common divisor, and Microsoft’s help describes it as returning the greatest common divisor of two or more integers.
Worked example: simplifying 84/126
The numerator 84 is in A1 and the denominator 126 in B1. What is the fraction in lowest terms?
- Calculate the divisor.
=GCD(A1,B1)returns 42. In a spreadsheet set to a locale that uses a decimal comma, arguments are separated with a semicolon instead:=GCD(A1;B1). - Divide the numerator.
=A1/GCD(A1,B1)gives 2. - Divide the denominator.
=B1/GCD(A1,B1)gives 3.
84/126 = 2/3.
Check. 2 × 42 = 84 and 3 × 42 = 126, and 2 and 3 have no common divisor other than 1.
There is a shortcut when the reduced fraction fits the format. Type =A1/B1 and apply # ?/?. The cell shows 2/3, but it stores 0.6666…, not the fraction. To get a reduced fraction you can copy as two numbers, use the three formulas above or the simplify fractions tool. To check a divisor with several numbers, the greatest common divisor calculator accepts more than two.
Fractions in Google Sheets
In Google Sheets, the format is applied through Format, Number, Custom number format. There you choose a format from the list or type your own and click Apply. Google’s help describes that route, the ? digit symbol and the / character for formatting numbers as a fraction, but it does not include a list of fraction types like Excel’s.
That is why it is worth testing the code on a cell with a known value. If you type 0.375 with # ?/? and see 3/8, the code works as in Excel. The stored value is still 0.375 and formulas use it the same way.
Sources
The names of the format types and the entry with a leading zero are those in the Microsoft help consulted on October 17, 2026. The values in the tables were calculated from the rules of each format and are not Microsoft examples.
- Microsoft, Display numbers as fractions: the fraction types and the entry with a leading zero, for example 0 9/12 (consulted October 17, 2026).
- Microsoft, GCD function: returns the greatest common divisor of two or more integers, with the syntax GCD(number1, [number2], …) (consulted October 17, 2026).
- Google, Format numbers in a spreadsheet: the route to a custom number format, the
?digit symbol and the/character for fractions (consulted October 17, 2026).