I know a number of bogleheads hold Total International Stock Fund in taxable accounts, with one advantage being claiming the foreign tax credit. There is a from 1116 which is fairly complex and also has to be replicated for the Alternative Minimum Tax if the foreign tax credit claimed is over $300 for a single taxpayer. Am I doing this calculation correctly to see how much TISM dividends are actually required to exceed the $300 threshold?

Using rough numbers, from the Vanguard site that gives foreign tax credit information (I think it is at the advisors site for some reason), it says that to calculate the foreign tax, it is the $ amount of the foreign dividends x 0.065 (6.5%). So I am assuming that at exactly $300 of foreign tax, this would represent $ 300 divided by 0.065 = $4600 of foreign dividends. Then hypothetically assuming a 2% dividend rate, this $4600 of foreign dividends would be generated from an investment in TISM of $4600 divided by 0.02, which is $230,000. So if the investment in TISM exceeds $230 K one would need Form 1116. Does this make sense?