Choose a mode: How much to save? — enter your goal, time horizon, starting balance, and interest rate to find the required monthly deposit. Or How long to save? — enter your monthly contribution to find the timeline. The chart shows your balance growing over time, split between contributions and interest earned.
Divide your target by the number of months, then adjust for interest using the future value of annuity formula: PMT = (FV − PV × (1+r)^n) × r / ((1+r)^n − 1). In practice, interest reduces the required monthly contribution — especially over longer timeframes. For a $20,000 goal in 3 years at 4% annual interest starting from zero, you need about $524/month. Without interest, it would be $556/month — the interest saves you $32/month and ~$1,150 total.
Time to goal = log(FV × r / PMT + 1) / log(1+r), where FV is your goal, PMT is monthly payment, and r is monthly rate. In practice: $300/month at 4% interest takes about 5.5 years to reach $20,000, or 21 years to reach $100,000. Doubling your contribution halves the timeline. A high interest rate compresses the timeline most noticeably for long goals — enter your numbers above to see the exact months.
Short-term (under 2 years): High-yield savings account (HYSA) or money market — 4–5% interest, fully liquid, zero principal risk. Medium-term (2–7 years): GICs/CDs or short-term bond funds for slightly higher rates in exchange for less liquidity. Long-term (7+ years): A diversified stock and bond portfolio will likely outperform savings accounts substantially, though with more volatility. Never put money in the stock market that you need within 2–3 years.
House down payment ($80,000 in 5 years, 4% interest): ~$1,213/month from zero, or ~$898/month with a $20,000 head start.
New car ($25,000 in 2 years, 4%): ~$1,004/month from zero.
Emergency fund ($15,000 in 18 months, 4%): ~$804/month from zero.
Vacation ($5,000 in 12 months, 4%): ~$408/month from zero.
Automate the transfer on payday so it happens before you can spend it. Put any windfalls (tax refund, bonus, gift) directly toward the goal. Use a dedicated account — mixing goal savings with everyday money leads to accidental spending. Incrementally increase contributions: a 1% raise often goes unnoticed if you save it automatically. Track progress monthly — seeing the balance grow is a powerful motivator that compounds your commitment as well as your interest.