Savings Goal Calculator

Knowing you want to save $50,000 is the easy part — knowing how much per month gets you there in three years (versus five) is where the planning gets concrete.

Enter your goal amount, your current savings balance, an annual return assumption, and the calculator returns the monthly contribution needed to hit the target by your chosen date. Or give it your monthly contribution and it tells you when you'll arrive. Compound interest is included, which matters more for long horizons than short ones.

The number to take seriously is the return assumption. A high-yield savings account at 4% behaves very differently from an S&P-tracking index fund at a long-run 7% real return. Both numbers are reasonable depending on your time horizon and risk tolerance — but using stock-market returns for a 1-year goal is how people end up surprised by drawdowns at the worst time.

The formula combines two parts. The starting balance grows with compound interest: starting × (1 + r)^t where r is the periodic rate and t is the period count. The monthly contributions form an annuity, with future value = contribution × ((1 + r)^t − 1) / r. Add the two and you have the future value. To solve for the contribution needed to hit a target, rearrange algebraically. The calculator does this once and recomputes whenever you change any input.

The pain this addresses: the gap between 'I want to save $100K' and 'here's the monthly amount.' For most people, that mental translation is unclear. The intuition that compound interest matters is widespread; the practical implications get fuzzy past 'put money in an index fund.' Concrete numbers — $X per month for Y years gets you to Z — produce different behavior than abstract goals. People save more when they know exactly what hitting their target requires.

Worked example: $50,000 goal, $0 starting balance, 7% annual return assumption (long-run S&P 500 real average), 5-year horizon. Monthly contribution required: $696. Bump the horizon to 10 years: $288/month. Drop the return to 4% (HYSA rate): 5 years $755, 10 years $336. The horizon dominates. A long-term goal at modest returns is achievable with reasonable contributions; a short-term goal at any return rate requires meaningful monthly cash. This is why retirement saving started early is so much easier than retirement saving started late.

Where the assumptions matter: returns aren't smooth. The S&P 500 averages around 7% real return over multi-decade horizons, but individual years vary from -38% (2008) to +29% (2013). A 5-year savings horizon ending in 2009 would have shown -20% returns instead of +40%. Use stock-market expected returns only for goals 10+ years out, where the bumpiness averages out. For shorter goals, use HYSA or CD rates and tolerate the lower number — the alternative is a meaningful chance of falling short of your target due to bad luck on timing.