18 millimeters in inches

Conversion formula
How to convert 18 millimeters to inches?

We know (by definition) that: $1\mathrm{mm}\approx 0.039370079\mathrm{in}$

We can set up a proportion to solve for the number of inches.

Now, we cross multiply to solve for our unknown $x$:

Conclusion: 18 ⁢ mm ≈ 0.708661422 ⁢ in

Conversion in the opposite direction

The inverse of the conversion factor is that 1 inch is equal to 1.41111111111111 times 18 millimeters.

It can also be expressed as: 18 millimeters is equal to $\frac{1}{\mathrm{1.41111111111111}}$ inches.

Approximation

An approximate numerical result would be: eighteen millimeters is about zero point seven one inches, or alternatively, a inch is about one point four zero times eighteen millimeters.