Fractions to Decimals: Every Common Conversion

Memorize these ten

1/2 = 0.5 · 1/3 = 0.333 · 1/4 = 0.25 · 1/5 = 0.2 · 1/6 = 0.166 · 1/8 = 0.125 · 1/10 = 0.1 · 1/12 = 0.0833 · 2/3 = 0.666 · 3/4 = 0.75.

The long-division method

Fraction to decimal is just top ÷ bottom. Any fraction with a denominator whose only prime factors are 2 and 5 terminates. Everything else repeats.

Decimal to fraction

Multiply until the decimal disappears, then simplify. 0.375 = 375/1000 = 3/8.

When to prefer which

Fractions are exact and easier for ratios. Decimals dominate money and measurement. Convert when the context changes.