1/8 Inch as a Decimal
Answer
0.125 in
1/8 in = 0.125 in = 3.175 mm
1/8 inch is one of the most common fractional sizes on a tape measure, drill index, and lumber yard chart. As a decimal it equals 0.125 inches, or 3.175 millimeters. It sits midway between 1/16 inch (0.0625 in) and 1/4 inch (0.25 in), and matches the thickness of standard hardboard, luan underlayment, and many tile spacers.
Try another fraction
/
Decimal
0.125
Millimeters
3.175 mm
Related values
| Value | Result |
|---|---|
| Decimal | 0.125 in |
| Millimeters | 3.175 mm |
| Centimeters | 0.3175 cm |
| Feet | 0.010417 ft |
How the conversion works
- Divide. Divide the numerator (1) by the denominator (8) to turn the fraction into a decimal.
- Decimal result. 1 ÷ 8 = 0.125. This is an exact, terminating decimal because 8 is a power of two.
- Convert to mm. Multiply 0.125 by 25.4 to convert to millimeters: 0.125 × 25.4 = 3.175 mm, the figure to use when matching a metric spec sheet.
Frequently Asked Questions
1/8 equals 0.125 as a decimal, found by dividing 1 by 8. It is one of the most common fractional sizes on tape measures, drill indexes, and lumber charts.
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