Or rather, come to think of it, an easier approach is to convert the inches to cm first. Then multiply the length, width, and height together. This will save time & be less confusing. Because then the cm

^{3}=mL.

Sorry for the confusion. Hope that makes sense.

Here is an example. Suppose your tank as 2.54 in wide, 2.54 in high, 2.54 in long.

There are 2.54 centimeters in an inch. So

2.54 in * 2.54cm / 2.54in = 1cm

1 cm * 1 cm * 1cm = 1 cm

^{3}1 cm

^{3} * 1 mL / 1cm

^{3} = 1 mL

1 mL * 1 L / 1000 mL = .001 L