Create a spreadsheet! I did this 25+ years ago to get my own customized answer to this question. One row per quarter (4 rows per year). Each row takes previous row's balance, adds % ROI, adds contributed savings to get the next row's balance forecast. Not a complicated spreadsheet. As each quarter passes, replace the forecasted/calculated balance with your actual savings balance.
Don't hard-code the % ROI and quarterly contribution in each row; put them in cells at the top. You can then play with % ROI and quarterly contribution values to see how much you'll have when. Take each rows balance and divide by (85-age) to get a conservative estimate of annual income if retired (conservatively assumes future ROI == inflation).
Fyi, I'm a 59 yo who knew ageism in hiring was coming and is so happy that my otherwise foolish self came up with a basic plan 25+ years ago to know if he was on track or not (and managed to stay well ahead of it). Helped with spending decisions too: if I was ahead, I'd buy that motorcycle; if not I didn't.
Don't hard-code the % ROI and quarterly contribution in each row; put them in cells at the top. You can then play with % ROI and quarterly contribution values to see how much you'll have when. Take each rows balance and divide by (85-age) to get a conservative estimate of annual income if retired (conservatively assumes future ROI == inflation).
Fyi, I'm a 59 yo who knew ageism in hiring was coming and is so happy that my otherwise foolish self came up with a basic plan 25+ years ago to know if he was on track or not (and managed to stay well ahead of it). Helped with spending decisions too: if I was ahead, I'd buy that motorcycle; if not I didn't.