you really need to know the amount of dividends (including capital gains) on which foreign taxes were withheld.
for example you might have gotten dividends from country A on which taxes were withheld and also dividends from country B on which there were no taxes withheld. Only Country A's dividends (which may or may not include capital gains) would go on the FTC form. The problem with many brokers and especially Regulated Investment Companies (RIC), which include Mutual Funds, ETFs, REITs, etc is that they only report the FTC and not the amount of income to report on the 1116. Only your broker can provide more info. For example, I had foreign taxes withheld on an international bond fund's dividends. the broker only reported the FTC. When I contacted them about the amount of income, they eventually got back and gave me a % to use.
