How to Use This Tool

Fraction to decimal converter

Type a fraction into the converter and it gives you the decimal equivalent, or enter a decimal to see it as a fraction. This page also includes a reference chart of common fractions and their decimal values, along with the method for doing these conversions by hand.

Common fractions and their decimals

How to convert fractions to decimals

The division method

Divide the numerator (top number) by the denominator (bottom number). That is all there is to it. 3/4 means 3 divided by 4, which equals 0.75. 7/8 means 7 divided by 8, which equals 0.875.

Examples

5/16 = 5 divided by 16 = 0.3125. This comes up when reading tape measures marked in sixteenths of an inch.

11/32 = 11 divided by 32 = 0.34375. Drill bit sizes are often in 32nds of an inch.

2/3 = 2 divided by 3 = 0.6666… The sixes repeat forever. This is a repeating decimal, often rounded to 0.667.

Mixed numbers

A mixed number like 3 1/2 has a whole number part and a fraction part. Convert just the fraction (1/2 = 0.5) and add it to the whole number: 3 + 0.5 = 3.5. Another example: 5 3/8 = 5 + 0.375 = 5.375.

How to convert decimals to fractions

The place value method

Write the decimal over the appropriate power of 10, then simplify. 0.75 = 75/100 = 3/4. 0.625 = 625/1000 = 5/8. The number of decimal places tells you the denominator: one place means 10, two places means 100, three places means 1,000.

Examples

0.4 = 4/10 = 2/5 (divide both by 2).

0.125 = 125/1000 = 1/8 (divide both by 125).

0.375 = 375/1000 = 3/8 (divide both by 125).

Repeating decimals

0.333… = 1/3. 0.1666… = 1/6. 0.142857142857… = 1/7. Repeating decimals always correspond to fractions, but the conversion requires recognizing the pattern. For most practical purposes, rounding to three or four decimal places and then converting is close enough.

When you need fraction-decimal conversions

Measurements and construction

Tape measures in the US are marked in fractions of an inch (1/4, 1/8, 1/16, 1/32). CNC machines, laser cutters, and CAD software use decimal inches. A board measured at 5 3/16 inches is 5.1875 inches in decimal. Getting this conversion wrong means parts that do not fit together.

Cooking

Recipes call for 1/3 cup or 3/4 teaspoon, but digital scales read in decimals. If you need to multiply 2/3 cup by 1.5, it helps to convert: 0.667 x 1.5 = 1.0 cup. Trying to multiply fractions mentally is slower and more error-prone for most people.

Finance

US stock prices were quoted in fractions (like 25 1/4) until 2001, when markets switched to decimals. Bond yields, interest rates, and financial formulas all work in decimals. Converting between the two shows up in older financial records and in some real estate calculations where prices are still discussed in fractional terms.

Education

Understanding the relationship between fractions and decimals is a core math skill. 1/4 = 0.25 = 25% are three representations of the same value. Knowing how to move between them helps with percentages, ratios, and proportions in any context.

Inch fraction to decimal chart

This table covers the fractions most commonly found on US tape measures and rulers, down to 32nds of an inch.

Tips for accurate conversions

• When a fraction has a denominator that is a power of 2 (2, 4, 8, 16, 32, 64), the decimal will terminate. 1/4 = 0.25, 5/32 = 0.15625. These are the fractions used on tape measures.
• When the denominator has factors of 3, 7, 11, or other primes besides 2 and 5, the decimal will repeat. 1/3 = 0.333…, 1/7 = 0.142857…, 1/6 = 0.1666…
• To simplify a fraction, divide both numerator and denominator by their greatest common factor. 6/8 becomes 3/4 (divide by 2). 15/25 becomes 3/5 (divide by 5).
• For quick mental math with eighths: 1/8 = 0.125, and each additional eighth adds 0.125. So 3/8 = 0.375, 5/8 = 0.625, 7/8 = 0.875.

Frequently asked questions

What is 1/3 as a decimal?

0.3333… (repeating). It is often rounded to 0.333 or 0.33 depending on the precision needed.

What is 5/8 as a decimal?

0.625. This is a common measurement on tape measures (5/8 of an inch = 0.625 inches = 15.875 mm).

How do I convert a repeating decimal to a fraction?

For simple repeating decimals: 0.333… = 1/3, 0.666… = 2/3, 0.111… = 1/9. For others, use algebra: if x = 0.142857142857…, then 1000000x = 142857.142857…, so 999999x = 142857, and x = 142857/999999 = 1/7.

What is the difference between a fraction and a ratio?

A fraction represents a part of a whole (3/4 means 3 out of 4 equal parts). A ratio compares two quantities (3:4 means 3 of one thing for every 4 of another). They use the same math but describe different relationships.

Can every decimal be written as a fraction?

Every terminating decimal and every repeating decimal can be written as a fraction. Irrational numbers like pi (3.14159…) and the square root of 2 (1.41421…) have decimals that neither terminate nor repeat, and they cannot be written as fractions.

What fraction is 0.875?

0.875 = 875/1000 = 7/8.

How do I add fractions with different denominators?

Find a common denominator, convert both fractions, then add. 1/3 + 1/4 = 4/12 + 3/12 = 7/12. Converting to decimals first (0.333 + 0.25 = 0.583) is sometimes faster.

Related conversion tools

• Percentage Calculator
• Inches to Centimeters Converter
• Millimeters to Inches Converter
• Cooking Converter

Measurement guides

• How Big Is X Inches? A Visual Size Guide From 1 to 16 Inches
• Inches Explained: Conversion Chart, Tools, and Real-World Examples

Formula & Explanation

To convert a fraction to a decimal, divide the numerator by the denominator. To convert a decimal to a fraction, find the smallest denominator (up to 64) such that numerator/denominator is closest to the decimal value.