1/4 Inch as a Decimal

Answer
0.25 in
1/4 in = 0.25 in = 6.35 mm

1/4 inch is one of the most familiar fractional marks on a tape measure, the second line after the whole inch. As a decimal it equals 0.25 inches, or 6.35 millimeters. It gives its name to the quarter-inch phone jack used on guitar cables and headphones, and it is a common plywood and dowel size, sitting exactly between 3/16 inch (0.1875 in) and 5/16 inch (0.3125 in).

Try another fraction
/
Decimal
0.25
Millimeters
6.35 mm

Related values

ValueResult
Decimal0.25 in
Millimeters6.35 mm
Centimeters0.635 cm
Feet0.020833 ft

How the conversion works

  1. Divide. Divide the numerator (1) by the denominator (4) to turn the fraction into a decimal.
  2. Decimal result. 1 ÷ 4 = 0.25. This is an exact, terminating decimal because 4 is a power of two.
  3. Convert to mm. Multiply 0.25 by 25.4 to convert to millimeters: 0.25 × 25.4 = 6.35 mm, the figure to use when matching a metric spec sheet.

Frequently Asked Questions

1/4 equals 0.25 as a decimal. Divide the numerator, 1, by the denominator, 4, to get this result. It is one of the most recognizable marks on a tape measure, sitting halfway between the whole inch and the 1/2 inch line.

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