SPF Calculation for Your Formula

Based on the ingredients in your formula, which includes multiple components that contribute to UV protection, it is not possible to calculate the exact SPF value through a simple calculation. The interaction and combined effect of ingredients like Titanium Dioxide, Zinc Oxide, and even Silk Mica Powder (which provides physical coverage) make a precise theoretical calculation difficult.

Based on experience with similar formulations, the estimated SPF for your formula is likely in the range of 20-25.

Contribution of Titanium Dioxide and Zinc Oxide

Both Titanium Dioxide and Zinc Oxide are physical sunscreens that protect against UV radiation:

• Titanium Dioxide 200nm EasyDisperse™: Primarily protects against UVB and short-wave UVA rays.
• Zinc Oxide 200nm EasyDisperse™: Provides good protection against long-wave UVA rays.

Using both ingredients together helps to achieve broad-spectrum protection against both UVA and UVB radiation. However, the specific SPF contribution of each ingredient in a complex formula like yours cannot be isolated or calculated individually without laboratory testing of the final product.