# 81 US customary cups in US gallons

## Conversion

81 US customary cups is equivalent to 5.0625 US gallons.^{[1]}

## 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.

$\frac{1\mathrm{uscup}}{81\mathrm{uscup}}\approx \frac{0.0625\mathrm{usgallon}}{x\mathrm{usgallon}}$Now, we cross multiply to solve for our unknown $x$:

$x\mathrm{usgallon}\approx \frac{81\mathrm{uscup}}{1\mathrm{uscup}}*0.0625\mathrm{usgallon}\to x\mathrm{usgallon}\approx 5.0625\mathrm{usgallon}$Conclusion: $81\mathrm{uscup}\approx 5.0625\mathrm{usgallon}$

## 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*.

## 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.