Pyrotechnic composition math
From PyroGuide
If you have a pyrotechnic composition that is measured in parts per total mix and you want to convert the ingredients as percentage of the total formula then this is mathematic formula you need to apply.
Note this pyrotechnic formula is an example only and does not represent any actual composition.
| Potassium nitrate | 60 |
| Charcoal | 38 |
| Sulfur | 24 |
| Aluminium powder | 8 |
| Dextrin | 2 |
| Total by weight | 132 |
First step is to add all the ingredients by weight to obtain a grand total. In the example above you would add 60 + 38 + 24 + 8 + 2 = 132. Now divide 100 by the grand total 132, this will return a of .7575
For each ingredient in your composition multiply it by the result of the equation above. For example:
| Ingredient | Calc | Result | Rounding |
| Potassium nitrate | 60 x .7575 | 45.45 | 45.5 |
| Charcoal | 38 x .7575 | 28.785 | 29 |
| Sulfur | 24 x .7575 | 18.18 | 18 |
| Aluminium powder | 8 x .7575 | 6.06 | 6 |
| Dextrin | 2 x .7575 | 1.515 | 1.5 |
| 100 |
In relation to the rounding, you may need to adjust the numbers as we have above to either the closes half a percent or full number to obtain exactly 100 percent.
Tools
By using a spreadsheet, the parts of the ingredients are readily converted to the percentages, and to the masses of the ingredients, when the total mass of the mixture is given. Also, the oxygen balance of the combustion can be easily calculated, when the appropriate redox reactions are known. When the OB is zero, the combustion is ideal (=stoichiometric).