Time to goal
How long, exactly? Given what you can save.
The other side of the goal-setting question. You know what you can save each month and the target you're aiming at — this tells you how many years it actually takes. If the answer is "14 years," that's information about whether the timeline or the lifestyle gets renegotiated first.
What your numbers say
Years to target
6 yr 10 mo
saving $500/mo
You'll contribute: $40,752
Growth: $9,248
Doubling the monthly
3 yr 9 mo
at $1,000/mo instead
The marginal year savings tells you how much income lever matters here.
The math
Solves the future-value annuity for n. With both starting balance and recurring contributions, no closed form — we step year by year and interpolate inside the year you cross the target.
The timeline tells you what to negotiate.