Not sure if this chart is right or not, but found this one.
replace [dot] with " . "
ebay[dot]com/itm/281338954836#viTabs_0
The description. If it's 400 mcg per drop, I think you would have to take 30 drops to get 12.5 mg. Because I was taking Nature's Way Kelp with Iodine capsules, and it was 600 mg of Kelp and 400 Mcg of Iodine and I was taking 30 capsules of Nature's Way Kelp with Iodine to get 12.5 mg of iodine.