IBU per Addition = [AA%] x [Ounces Hops] x [Boil Time Factor]
Add the IBU from each addition for total predicted IBU
Boil Time Factor for 5 gallon batches by time of hop addition:
| MIN | BTF |
| 60+ | 4.0 |
| 55 | 3.5 |
| 50 | 3.1 |
| 45 | 2.7 |
| 40 | 2.2 |
| 35 | 1.8 |
| 30 | 1.4 |
| 25 | 1.2 |
| 20 | 1.1 |
| 15 | 1.0 |
| 10 | 0.8 |
| 5 | 0.7 |
| Whirlpool | 0.6 |
