I was searching for a long time, but I wasn't able to find a solution. There's one user (pgus ?) did state that he found a solution, but unfortunately he never shared with community how he did it.
So let's repeat:
I've a banner printing business and I need that customers have to enter length and height of the banner and the the square meters are calculated automatically. And of course then the end price is "price per sqm" x "calculated square meters". Should not to be too difficult but I can't figure out how to do this.
Is anyone able to provide a reproducible solution ?
Thanks in advance.