0.25 as a Fraction of an Inch

Answer
1/4 in
0.25 in = 1/4 in (1/64 in) = 6.35 mm

0.25 inches equals 1/4 inch, one of the four main marks on every tape measure alongside 1/2, 3/4, and the whole inch. It is a standard bolt and lag screw diameter, a common nominal plywood thickness, and a size found on almost every fractional drill index and socket set. Because a quarter inch is an exact multiple of 1/16 in, it reads as 1/4 in whether you round to 1/16, 1/32, or 1/64 precision.

Try another decimal
Nearest 1/16
1/4"
Nearest 1/32
1/4"
Millimeters
6.35 mm

Related values

ValueResult
Nearest 1/8 in1/4 in
Nearest 1/16 in1/4 in
Nearest 1/32 in1/4 in
Nearest 1/64 in1/4 in
Millimeters6.35 mm
Centimeters0.635 cm
Feet0.020833 ft

How the conversion works

  1. Split the decimal. Separate the whole-number part from the decimal part. 0.25 has no whole-number portion, so the full value goes into the fraction conversion.
  2. Multiply by precision. Multiply the decimal by the denominator you want, 16, 32, or 64, then round to the nearest whole number. 0.25 × 16 = 4 exactly, with no rounding required.
  3. Simplify. Reduce the fraction using the greatest common divisor of numerator and denominator. 4/16 shares a factor of 4, which simplifies down to 1/4.
  4. Verify in mm. Multiply the decimal inches by 25.4 to check the metric equivalent: 0.25 × 25.4 = 6.35 mm.

Frequently Asked Questions

0.25 inches equals 1/4 in. This is exact at every common precision, 1/16, 1/32, and 1/64, because a quarter inch is a round number of sixteenths with nothing to round away.

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