Step 4: SPF Table

Picture of SPF Table
If using the zinc oxide or titanium dioxide separately, use the following table to determine your measurements.
I don't have a chart for using the blended powder, but it starts off with SPF35 on its own.  

For example, 8oz. (weighed) of lotion + .8oz of titanium micronized dioxide (weighed) = SPF20+
The Micronized TD is 10% of the original amount of lotion used (not the finished weight).

If you used 8oz of lotion + .8oz of Micronized ZO, the SPF would be 11-12.

If it's still too confusing, ask!

Concentration of
Sunscreens & SPF
(SPF 2-5)
(SPF 6-11)
(SPF 12-19)
Ultra High
(SPF >20)
Titanium Dioxide <4 % 8 % 12 % 20 %
Titanium Dioxide, Micronized 2 % 4 % 6 % 10 %
Zinc Oxide 5 % 10 % 15 % 25 %
Zinc Oxide, Micronized 3 % 7.5 % 12 % 20 %

This chart is to provided by my supplier. I can not do any testing internally. Just to be used as a guideline.
manicmonday2 months ago

So, sounds like your saying use lotion to zinc oxide 4 to 1 would make spf-20, right?

If I use 2 cups of olive oil, 1 cup of coconut oil, 1 cup of beeswax then how much zinc oxide do I use . I used 8 tbsps. . is this too much?

CristinaD4 months ago

I purchased a mineral sunscreen what lists 8% TiO2 as the only active ingredient and the product is labeled spf 25.. why?

Hello! If my batch of lip balm weighs 64 ounces, how much zinc oxide would I need to add to get an spf of 20? Is their a formula I can use to calculate this? I see I would need 25% zinc to get spa 20 but what is the calculation? Thanks

Roxanne_b3 years ago
Thank you for this instructable I'm very excited to try it!!

However I'm very confused . . . is the percentage the percentage of the lotion? so for example use 25% of the overall weight of the lotion zinc oxide and that would be SPF 20?
Heptron5 years ago
I did some quick math in Excel and it seems that this table of data generates curves with exponential growth.
Do you know how well this hold true outside the data set?