How do I calculate resulting pitch from Sliding Timescale/Pitch Shift?

I want to calculate the frequency resulting from the percent change in the Sliding Timescale/Pitch Shift Effect/Tool on a calculator. I had a website do it, but I lost that link. Basically, I put in -1.818 to get 440Hz to change to 432Hz. How do I get a calculator to show me that? I think 50% is equal to x2.

I just use the results of the Change Pitch effect - it has a handy calculator built in. Then I can take the number and transfer it to the Sliding Stretch.