0.8125 as a Fraction of an Inch

Answer
13/16 in
0.8125 in = 13/16 in (1/64 in) = 20.6375 mm

0.8125 inches equals 13/16 inch, most familiar as the size of a standard spark plug socket found in nearly every automotive toolbox. It also appears on fractional drill and tap drill charts for larger fasteners. Sitting exactly between 3/4 in (0.75 in) and 7/8 in (0.875 in), it stays 13/16 in whether you round to 1/16, 1/32, or 1/64 precision.

Try another decimal
Nearest 1/16
13/16"
Nearest 1/32
13/16"
Millimeters
20.6375 mm

Related values

ValueResult
Nearest 1/8 in7/8 in
Nearest 1/16 in13/16 in
Nearest 1/32 in13/16 in
Nearest 1/64 in13/16 in
Millimeters20.6375 mm
Centimeters2.0638 cm
Feet0.067708 ft

How the conversion works

  1. Split the decimal. Separate the whole-number part from the decimal part. 0.8125 has no whole-number portion, so the entire value converts into the fraction.
  2. Multiply by precision. Multiply the decimal by the denominator you want, 16, 32, or 64, then round to the nearest whole number. 0.8125 × 16 = 13 exactly, with nothing left to round.
  3. Simplify. Reduce the fraction using the greatest common divisor of numerator and denominator. 13 and 16 share no common factor, so 13/16 is already in lowest terms.
  4. Verify in mm. Multiply the decimal inches by 25.4 to check the metric value: 0.8125 × 25.4 = 20.6375 mm.

Frequently Asked Questions

0.8125 inches equals 13/16 in. That answer is exact at 1/16, 1/32, and 1/64 precision because 0.8125 is already a whole number of sixteenths.

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