639 US gallons in imperial gallons

Conversion formula
How to convert 639 US gallons to imperial gallons?

We know (by definition) that: $1\mathrm{usgallon}\approx 0.832674184628989\mathrm{imperialgallon}$

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

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

Conclusion: 639 ⁢ usgallon ≈ 532.0788039779239 ⁢ imperialgallon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 imperial gallon is equal to 0.00187942085368522 times 639 US gallons.

It can also be expressed as: 639 US gallons is equal to $\frac{1}{\mathrm{0.00187942085368522}}$ imperial gallons.

Approximation

An approximate numerical result would be: six hundred and thirty-nine US gallons is about five hundred and thirty-two point zero eight imperial gallons, or alternatively, a imperial gallon is about zero times six hundred and thirty-nine US gallons.