There’s a number of calculators out there, from the very simple. (E.g. Moneychimp’s compound interest calculator) to the more complex historical simulators (e.g. cFireSim or FireCalc, which model $ and returns against historical data).
If you just want a ballpark, ‘when might my current ‘stache’ grow to be $XXX,XXX” I’d play around with a compound interest calculator.
Or.... you could do what I do - and make a spreadsheet. Column A will be your current principle, column B = annual savings, and then columns C, D, E... can be (A +B) * expected market gain (e.g. 6% ‘real’ returns). You can do a column for a bunch of different returns. Then plot.
Obviously the spreadsheet method won’t be realistic as markets don’t move upwards at a steady trend, but it will give you a rough idea of where you are and how long it will take you to get to where you want to go under various scenarios.
