Inch Fraction Calculator

Convert decimal inches to fractions or fractions to decimal. Choose 1/8 to 1/64 precision. See mm, cm, and feet + inches equivalents.

๐Ÿ”ข Inch Fraction Calculator

FRACTION

Inch Fraction3 3/8"

DECIMAL

Decimal Inches3.3750"

METRIC

Millimeters85.73 mm
Centimeters8.573 cm

๐Ÿ’ก Decimal to Fraction Inch Conversion

Inch fractions use denominators that are powers of 2: halves (1/2), quarters (1/4), eighths (1/8), sixteenths (1/16), thirty-seconds (1/32), and sixty-fourths (1/64). They're the standard on US tape measures, rulers, and construction plans. For math with fractional measurements, try our feet and inches calculator or convert areas with our square footage calculator.

How to Convert Decimal to Fraction

  1. Separate the whole number: 3.375 โ†’ whole = 3, decimal = 0.375
  2. Multiply decimal by your precision denominator: 0.375 ร— 16 = 6
  3. Place result over denominator: 6/16
  4. Simplify: 6/16 = 3/8 (divide both by GCD of 2)
  5. Result: 3 3/8"

Decimal to Inches Chart

FractionDecimalmm
1/16"0.06251.59
1/8"0.1253.18
3/16"0.18754.76
1/4"0.256.35
5/16"0.31257.94
3/8"0.3759.53
7/16"0.437511.11
1/2"0.512.70
9/16"0.562514.29
5/8"0.62515.88
11/16"0.687517.46
3/4"0.7519.05
13/16"0.812520.64
7/8"0.87522.23
15/16"0.937523.81
1"1.025.40

Inches to Metric Conversion

mm = inches ร— 25.4 | cm = inches ร— 2.54

  • 1/4" = 6.35 mm
  • 1/2" = 12.70 mm
  • 1" = 25.40 mm = 2.54 cm
  • 6" = 152.40 mm = 15.24 cm
  • 12" = 304.80 mm = 30.48 cm = 1 foot

Reading a Tape Measure

Tape measure markings are different lengths to indicate fraction size:

  • Longest marks: whole inches (1", 2", 3"โ€ฆ)
  • Next longest: 1/2" marks
  • Medium marks: 1/4" marks
  • Short marks: 1/8" marks
  • Shortest marks: 1/16" marks

Count the smallest marks past the last whole inch. If you count 7 marks of 1/16" size, the reading is 7/16".

3.375" = 3 3/8" = 85.73 mm. At 1/16 precision: 3 6/16" = 3 3/8" (simplified). In Fraction โ†’ Decimal: 3 3/8" = 3.375".

Inch Fraction Calculator FAQ