21 liters in US gallons

Conversion formula
How to convert 21 liters to US gallons?

We know (by definition) that: $1\mathrm{liter}\approx 0.264172052358148\mathrm{usgallon}$

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: 21 ⁢ liter ≈ 5.547613099521108 ⁢ usgallon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US gallon is equal to 0.180257704 times 21 liters.

It can also be expressed as: 21 liters is equal to $\frac{1}{\mathrm{0.180257704}}$ US gallons.

Approximation

An approximate numerical result would be: twenty-one liters is about five point five four US gallons, or alternatively, a US gallon is about zero point one eight times twenty-one liters.