Fraction Decimal Chart

Fraction to MM Chart

Convert inch fractions to millimeters when an inch measurement needs to match metric hardware, drawings, or parts.

Fraction to MM Converter

Use the main calculator to enter fractions, decimals, mixed inch values, or millimeters. The chart below gives quick reference values for this page.

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Inch Fractions to Millimeters

Common inch fractions converted to decimal inches and millimeters.

FractionDecimal inchesMillimetersNearest 1/64
1/64 0.0156 0.397 1/64
1/32 0.0313 0.794 1/32
3/64 0.0469 1.191 3/64
1/16 0.0625 1.588 1/16
5/64 0.0781 1.984 5/64
3/32 0.0938 2.381 3/32
7/64 0.1094 2.778 7/64
1/8 0.1250 3.175 1/8
9/64 0.1406 3.572 9/64
5/32 0.1563 3.969 5/32
11/64 0.1719 4.366 11/64
3/16 0.1875 4.763 3/16
13/64 0.2031 5.159 13/64
7/32 0.2188 5.556 7/32
15/64 0.2344 5.953 15/64
1/4 0.2500 6.350 1/4
5/16 0.3125 7.938 5/16
3/8 0.3750 9.525 3/8
7/16 0.4375 11.113 7/16
1/2 0.5000 12.700 1/2
9/16 0.5625 14.288 9/16
5/8 0.6250 15.875 5/8
11/16 0.6875 17.463 11/16
3/4 0.7500 19.050 3/4
13/16 0.8125 20.638 13/16
7/8 0.8750 22.225 7/8
15/16 0.9375 23.813 15/16
1 1.0000 25.400 1

Note: Values are based on 1 inch = 25.4 millimeters.

Formula

  • Convert the fraction to a decimal first.
  • Multiply decimal inches by 25.4.
  • Example: 3/8 inch equals 9.525 mm.

When metric values matter

  • Use millimeters when buying metric hardware.
  • Use decimal inches for inch-based drawings.
  • Do not round too early when stacking measurements.

All Conversion Charts

Decimal to Fraction ChartFraction to Decimal CalculatorDecimal Inch ChartInch Fraction CalculatorMM to Inches Fraction ChartMM to Inches Fraction CalculatorInch Decimal to Fraction CalculatorFraction to Percent ChartRuler Fraction ChartPrintable Fraction Decimal Chart1/16 Fraction Chart1/32 Fraction ChartPrintable 1/64 Chart