How to convert a fraction to a decimal
To turn a fraction into a decimal, divide the top number by the bottom number: numerator ÷ denominator. For 3/8, that is 3 ÷ 8 = 0.375. Every fraction equals a decimal that either terminates or repeats.
A fraction bar is simply another way of writing a division sign, so nothing is being transformed — the two notations describe the same quantity. That also explains why an improper fraction such as 9/4 converts to a value greater than 1 (2.25), while any fraction with a numerator smaller than its denominator lands between 0 and 1. The division behind it is ordinary long division, which the long division calculator will show step by step.
Terminating vs. repeating decimals
If the denominator's only prime factors are 2 and 5, the decimal terminates (like 3/8 = 0.375). Otherwise it repeats, such as 1/3 = 0.333… To go the other direction, use the decimal to fraction calculator.
The reason is that our number system is base 10, and 10 factors into 2 × 5. A denominator built only from those primes can be scaled up to a power of ten, which is what a terminating decimal is. Reduce the fraction to lowest terms before applying the test, or a common factor may hide the true denominator.
How to use this calculator
Enter the numerator (top) and denominator (bottom) of your fraction. The decimal value appears instantly, rounded for display. The denominator cannot be zero, since division by zero is undefined.
Because repeating decimals are cut off at the displayed precision, the value you see for something like 2/3 is very slightly short of the true figure. For exact work keep the fraction in its original form and convert only at the final step, so rounding does not accumulate through the calculation. Multiply the decimal by 100 and you have a percentage, which is where the percentage calculator takes over.
Frequently asked questions
- What is 3/8 as a decimal?
- 3/8 equals 0.375, found by dividing 3 by 8.
- How do I convert any fraction to a decimal?
- Divide the numerator by the denominator. The quotient is the decimal value.
- Why can't the denominator be zero?
- Dividing by zero is undefined, so a fraction must have a non-zero denominator.
- What is a repeating decimal?
- A repeating decimal has a digit pattern that goes on forever, like 1/3 = 0.333…
- How do I convert a mixed number such as 2 3/8?
- Convert the fractional part on its own and add the whole number back: 3 ÷ 8 = 0.375, so 2 3/8 = 2.375. Alternatively turn it into an improper fraction first — 19/8 — and divide that instead, which gives the same answer.