Savings Goal

Given a target amount and a deadline, this calculator works out the monthly contribution required. The naive version divides the target by the number of months. The useful version accounts for interest earned along the way, which reduces the contribution needed — modestly over a short horizon, substantially over a long one.

Which horizon you are on should change where the money sits. For a goal a year or two away, the return matters far less than certainty: a market drop just before the deadline can leave you short with no time to recover, so a high-yield savings account or similar is the appropriate home even though the return is lower. For a goal a decade or more out, keeping the money in cash is the greater risk, because inflation erodes purchasing power over that span while a long horizon gives volatile assets time to recover.

Set the target in the money of the day you will spend it. A goal defined in today's prices will fall short by the time you get there if the horizon is long, because the thing you are saving for will cost more. Inflating the target to the expected future cost, or planning with a real rather than nominal return, keeps the plan honest.

Automating the transfer is the change that most reliably works. A standing transfer on payday removes the monthly decision, and the decision is where plans fail — not the arithmetic. Everything runs in your browser — no login, no upload, and no figure you enter leaves the page.