Length units calculator & converter tool
Conversions Table
Equivalent of 18 Inch: |
| 457.19975311213 Millimeter |
| 45.719975311213 Centimeter |
| 0.45719975311213 Meter |
| 0.00045719975311213 Kilometer |
| 1.5000723899609 Foot |
| 0.00028409066779104 Mile |
| 0.50017652990467 Yard |
| 0.00024688786668055 Nautical Mile |
Inch / Millimeter Units Definition
Inch
The inch (symbol: ″ (double prime) or po in French-speaking Canada) is a unit of length dating back to the Middle Ages.Its dimensional value has varied over time, across regions and across countries.Since 1959, following an English compromise, the English inch — also called the “international technical inch” — has been exactly 2.54 cm, or one twelfth of a foot or one thirty-sixth (1⁄36) of a yard. For historical reasons, other definitions of the inch are still in force in certain areas.
Millimeter
The millimeter mm (thousandth of a meter, 10-3m). It is difficult to manipulate with your fingers an object smaller than 1mm. The micrometer or micron µm (thousandth of a mm, 10-6m): the thickness of soap bubbles, when they make pretty colors, is a few microns.