How many bags of mix to do shower base 3x5

How deep is it ?

And how big are the bags. I've seen them come in two different sizes.

Do the math, L X W X H and find out how many cubic feet you need rounding up. Better to throw some out than come up short.

Here is a concrete calculator:

https://www.quikrete.com/calculator/main.asp?gclid=CKrQpuX_m8wCFUpZhgod4PcHuQ

Enter your information and it will calculate total bags needed. Add 1 additional bag to the total suggested for waste and to be absolutely sure you don't end up short on your pour as Smoothy alluded, too.

Mark