A fraction represents a part of a whole and is written as a numerator over a denominator — for example, 3/4. Converting a fraction to its decimal equivalent means performing the division: 3 ÷ 4 = 0.75. Some fractions produce terminating decimals that end after a fixed number of digits, like 1/8 = 0.125. Others produce repeating decimals that go on forever with a repeating pattern, like 1/3 = 0.333… Understanding both forms helps you work fluidly between different mathematical representations.
The reverse conversion — decimal to fraction — requires identifying the place value of the last digit (tenths, hundredths, thousandths, and so on) and then simplifying the resulting fraction. For example, 0.6 = 6/10 = 3/5. Repeating decimals require an algebraic trick: 0.333… can be represented as x = 0.333…, so 10x = 3.333…, giving 9x = 3 and x = 1/3. This tool uses a continued-fraction algorithm to find the best rational approximation for any decimal you enter, producing a simplified fraction that is accurate to within a billionth.
Select the direction you need using the two mode buttons at the top of the card. F → D mode converts a fraction to a decimal: type your numerator into the top field and your denominator into the bottom field, then press CONVERT or hit Enter. The result appears on the green CRT display below, showing the exact decimal value. If the denominator is zero, the tool immediately flags a division-by-zero error.
Switch to D → F mode to go the other way. Enter any decimal — positive, negative, whole, or fractional — into the input field and press CONVERT. The display shows the fraction in its simplest form alongside a confirmation decimal so you can verify the accuracy of the conversion at a glance. Both modes clear automatically when you switch directions, keeping the interface clean and uncluttered.