If it's about calculating the exact pure alcohol content, then I have to pass. I thought this was about how much booze you can add to a ganache. Adding a 5% liqueur should be enough.
When adding booze to hot cream to pour over chocolate, which is making a ganache, you have to realize that alcohol already starts to evaporate at 70°C. So, a calculation is not enough.
There's also a possibility to get even more flavor by infusing your cream with the taste that's already in booze, so you can keep the liqueur content low. For instance;
- Frangelico (hazzlenut liqueur); infuse (from the fire) the boiled cream with powdered hazzlenuts for 20 minutes and sieve.
- Amaretto (bitter almond liqueur); infuse with powdered almonds
- Kahlua (coffee liqueur); add a little instant coffee powder
- Grand Marnier (orange liqueur); infuse with orange zeste