Decimal to Fraction Converter
Convert any terminating decimal (e.g., 0.125, 3.4) into its simplest fractional form. Enter your decimal number below to get the results as a **simplified fraction**, an **improper fraction**, and a **mixed number**.
Conversion Results
Simplified Fraction (Lowest Terms)
Improper Fraction
Mixed Number
Step-by-Step Simplification
The Three Steps to Converting Decimals to Fractions
The key principle is that the place value of the last digit in the decimal determines the denominator (a power of ten) of the initial fraction.
- Determine Initial Fraction ($A/B$): Identify the place value of the last digit in the decimal.
- If the decimal is 0.7 (tenths place), the denominator is 10. Fraction: $\frac{7}{10}$
- If the decimal is 0.75 (hundredths place), the denominator is 100. Fraction: $\frac{75}{100}$
- If the decimal is 0.125 (thousandths place), the denominator is 1000. Fraction: $\frac{125}{1000}$
- Find the Greatest Common Divisor (GCD): The GCD is the largest number that divides evenly into both the numerator and the denominator. This is the crucial step for simplification.
- Simplify: Divide both the numerator and the denominator by the GCD to get the simplified fraction (lowest terms).
Handling Decimals with a Whole Number
For a number like $4.3$, treat the whole number (4) and the decimal part (0.3) separately. $0.3 = \frac{3}{10}$. The mixed number is $4\frac{3}{10}$.
To find the improper fraction, convert the mixed number: $4\frac{3}{10} = \frac{(4 \times 10) + 3}{10} = \frac{43}{10}$.
Converting Repeating Decimals
This calculator primarily targets terminating decimals. Converting repeating decimals (like $0.\overline{6}$) requires a different algebraic technique:
- Let $x$ equal the repeating decimal (e.g., $x = 0.666...$).
- Multiply $x$ by $10^n$, where $n$ is the number of repeating digits (e.g., $10x = 6.666...$).
- Subtract the original equation from the new one ($10x - x = 6.666... - 0.666...$).
- Solve for $x$: $9x = 6$, so $x = \frac{6}{9}$, which simplifies to $\frac{2}{3}$.
Frequently Asked Questions (FAQ)
What is the fastest way to convert a decimal to a fraction?
How do you convert a decimal like 0.333... (repeating) to a fraction?
How do I convert a decimal that includes a whole number (e.g., 5.4) to a fraction?
What is the Greatest Common Divisor (GCD) in fraction conversion?
Formula (LaTeX) + variables + units
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\\frac{${num}}{${den}}
${mixedWhole} \\frac{${mixedNumerator}}{${simplifiedDenominator}}
\\frac{${initialNumerator}}{${initialDenominator}}
\\frac{${initialNumerator} \\div ${commonDivisor}}{${initialDenominator} \\div ${commonDivisor}} = \\frac{${simplifiedNumerator}}{${simplifiedDenominator}}
\\frac{(${wholePart} \\times ${simplifiedDenominator}) + ${simplifiedNumerator}}{${simplifiedDenominator}} = \\frac{${improperNumerator}}{${simplifiedDenominator}}
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.