# Calculating concentration of a powder in a liquid

I'm trying to determine how to calculate proper measurements for a 5% concentration of a vitamin C ester powder (ascorbyl palmitate) mixed in a 50/50 carrier oil mixture (jojoba oil/squalane oil) with 2% vitamin E oil (α-Tocopherol).

The powder is measured in mg and the oils in mL.

Densities:

• Jojoba oil = 868 mg/mL
• Squalane oil = 810 mg/mL
• α-Tocopherol = 950 mg/mL
• Ascorbyl palmitate = 1.2 g/cm3

I want to create a concentration of 5% powder in 118 mL of oil. However, the total volume of the entire mixture should not exceed 118 mL, so I would need to also know how much oil to subtract before adding the powder to get the exact final volume desired.

How would I correctly calculate both the quantity of powder to mix in and the proper starting volume of the combined carrier oils?