21 US gallons in imperial cups

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

We know (by definition) that: $1\mathrm{usgallon}\approx 13.3227869540638\mathrm{brcup}$

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

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

Conclusion: 21 ⁢ usgallon ≈ 279.7785260353398 ⁢ brcup

Conversion in the opposite direction

The inverse of the conversion factor is that 1 imperial cup is equal to 0.00357425573066921 times 21 US gallons.

It can also be expressed as: 21 US gallons is equal to $\frac{1}{\mathrm{0.00357425573066921}}$ imperial cups.

Approximation

An approximate numerical result would be: twenty-one US gallons is about two hundred and seventy-nine point seven seven imperial cups, or alternatively, a imperial cup is about zero times twenty-one US gallons.