21 US customary cups in imperial gallons

Conversion formula
How to convert 21 US customary cups to imperial gallons?

We know (by definition) that: $1\mathrm{uscup}\approx 0.0520421365393118\mathrm{imperialgallon}$

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: 21 ⁢ uscup ≈ 1.0928848673255478 ⁢ imperialgallon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 imperial gallon is equal to 0.915009467051318 times 21 US customary cups.

It can also be expressed as: 21 US customary cups is equal to $\frac{1}{\mathrm{0.915009467051318}}$ imperial gallons.

Approximation

An approximate numerical result would be: twenty-one US customary cups is about one point zero nine imperial gallons, or alternatively, a imperial gallon is about zero point nine two times twenty-one US customary cups.