100 millimeters in inches

Conversion formula
How to convert 100 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: 100 ⁢ mm ≈ 3.9370079000000002 ⁢ in

Conversion in the opposite direction

The inverse of the conversion factor is that 1 inch is equal to 0.254 times 100 millimeters.

It can also be expressed as: 100 millimeters is equal to $\frac{1}{\mathrm{0.254}}$ inches.

Approximation

An approximate numerical result would be: one hundred millimeters is about three point nine four inches, or alternatively, a inch is about zero point two five times one hundred millimeters.