81 US customary cups in US gallons

Conversion formula
How to convert 81 US customary cups to US gallons?

We know (by definition) that: $1\mathrm{uscup}\approx 0.0625\mathrm{usgallon}$

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

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

Conclusion: 81 ⁢ uscup ≈ 5.0625 ⁢ usgallon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US gallon is equal to 0.197530864197531 times 81 US customary cups.

It can also be expressed as: 81 US customary cups is equal to $\frac{1}{\mathrm{0.197530864197531}}$ US gallons.

Approximation

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