861 imperial gallons in US customary cups
Result
The conversion result is: 861 imperial gallons is equivalent to 16544.2861737549 US customary cups.[1]
Conversion formula
How to convert 861 imperial gallons to US customary cups?
We know (by definition) that: 1 imperialgallon ≈ 19.2151988080777 uscup.
We can set up a proportion to solve for the number of US customary cups.
1 imperialgallon / 861 imperialgallon ≈ 19.2151988080777 uscup / x uscup
Now, we cross multiply to solve for our unknown x:
x uscup ≈ (861 imperialgallon / 1 imperialgallon) * 19.2151988080777 uscup → x uscup ≈ 16544.286173754903 uscup
Conclusion:
861 imperialgallon ≈ 16544.286173754903 uscup

Conversion in the opposite direction
The inverse of the conversion factor is that 1 US customary cup is equal to 6.04438287332309e-05 times 861 imperial gallons.
It can also be expressed as: 861 imperial gallons is equal to 1 / 6.04438287332309e-05 US customary cups.
Approximation
An approximate numerical result would be: eight hundred and sixty-one imperial gallons is about sixteen thousand, five hundred and forty-four point two nine US customary cups, or alternatively, a US customary cup is about zero times eight hundred and sixty-one imperial gallons.
Footnotes
[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).
Results may contain small errors due to the use of floating point arithmetic.