840 meters in millimeters

Conversion formula
How to convert 840 meters to millimeters?

We know (by definition) that: $1\mathrm{m}=1000\mathrm{mm}$

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

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

Conclusion: 840 ⁢ m = 840000 ⁢ mm

Conversion in the opposite direction

The inverse of the conversion factor is that 1 millimeter is equal to 1.19047619047619e-06 times 840 meters.

It can also be expressed as: 840 meters is equal to $\frac{1}{\mathrm{1.19047619047619e-06}}$ millimeters.

Approximation

An approximate numerical result would be: eight hundred and forty meters is about eight hundred and forty thousand millimeters, or alternatively, a millimeter is about zero times eight hundred and forty meters.