text: how can i accurately determine the p/e ratio and forward p/e ratio of etf's investing in foreign indexes? also, which etf's that invest in country specific indexes have the lowest p/e ratio's? thanks!!! you would have to add up all the prices of shares times the number of shares for the proper weighting they recive in the index or etf. then add up all the earnings per share times the number of shares. then divide those two numbers.   the forward p/e you would have to estimate not only what those companies will make next year, but what the companies  are added and what are dropped. this is not realy even possible assuming you had a good crystal ball to estimate what a company would make if you knew exactly which company to calculate it for.  that is a lot of work.