Large Purchase Timeline Calculator

If Savings Account Rate is also 0%, the goal is never reached from contributions or interest, and Weeks to Goal shows the calculator's 5,200-week (100-year) cap as a "not realistically reachable" signal. If Savings Account Rate is above 0%, Currently Saved can still grow through compounding alone and may eventually reach Item Cost, though typically far more slowly than with regular weekly deposits.

Yes, directionally -- more interest means your balance grows faster between deposits, so it reaches Item Cost sooner or at the same time, never later. Because Weeks to Goal is a whole number of weeks, though, a small rate change sometimes doesn't shift the rounded week count at all; the effect shows up more clearly over a wider range of rates or a longer savings timeline.

Interest Earned is only calculated once the simulation actually reaches Item Cost within the 5,200-week cap. If your Weekly Savings Amount and Savings Account Rate combination can't close the gap within that 100-year horizon, Weeks to Goal reports the cap instead of a real payoff week, and Interest Earned is left at $0 rather than reporting a number from a payoff that never happens.

Simple division ignores compounding: it's exactly correct when Savings Account Rate is 0%. Above 0% this calculator simulates the balance growing by that rate every week before adding your deposit, so interest chips away at the gap. How much that matters depends almost entirely on how long you're saving. At the defaults -- a $2,000 item, $100 a week -- the answer is 17 weeks at every rate from 0% to 15%, because four months is too short for interest to move a whole-week count. Over a longer horizon it's decisive: $50,000 with $10,000 already saved and $100 a week takes 400 weeks at 0%, 320 weeks at 4.5%, and 223 weeks at 15%.