31 imperial gallons in US gallons
Result
The conversion result is: 31 imperial gallons is equivalent to 37.2294476906505 US gallons.[1]
Conversion formula
How to convert 31 imperial gallons to US gallons?
We know (by definition) that: 1 imperialgallon ≈ 1.20094992550486 usgallon.
We can set up a proportion to solve for the number of US gallons.
1 imperialgallon / 31 imperialgallon ≈ 1.20094992550486 usgallon / x usgallon
Now, we cross multiply to solve for our unknown x:
x usgallon ≈ (31 imperialgallon / 1 imperialgallon) * 1.20094992550486 usgallon → x usgallon ≈ 37.22944769065066 usgallon
Conclusion:
31 imperialgallon ≈ 37.22944769065066 usgallon

Conversion in the opposite direction
The inverse of the conversion factor is that 1 US gallon is equal to 0.0268604575686771 times 31 imperial gallons.
It can also be expressed as: 31 imperial gallons is equal to 1 / 0.0268604575686771 US gallons.
Approximation
An approximate numerical result would be: thirty-one imperial gallons is about thirty-seven point two two US gallons, or alternatively, a US gallon is about zero point zero three times thirty-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.