Many mutual funds (like those in a 401k) have dividends or other returns that are automatically reinvested. Is there a good online resource to determine how much my shares grew — includiung dividends — between two time periods?
I had found data from SeekingAlpha and attempted to do the math manually, but I don’t trust myself. I did also find [Buy Upside](https://www.buyupside.com/stockreturncalculator/stockreturncalcinput.php) which seems like it might be good? Would any of you have a better recommendation, aside from contacting an accountant?