Result
- Total you'll contribute$43,452.33
- Interest earned$6,547.67
- Current balance grows tobefore adding monthly contributions$6,416.79
- Time to goal60 months
How to use this calculator
- Enter your savings goal — be specific about the dollar amount.
- Type your current balance for this goal (separate accounts is best).
- Set the deadline in years.
- Pick a return rate matching where the money lives (HYSA, brokerage, etc.).
About this tool
Set a savings goal — house down payment, car, big trip, kid's college — and the calculator works backwards: given your current balance, time horizon, and expected return, what monthly contribution gets you there? Lower the expected return for safer goals (a savings account: 1-5%), raise it for aggressive ones (a brokerage account in stocks: 6-8%). The math accounts for compounding on both your existing balance and the new contributions, so the monthly number is realistic, not just (target ÷ months).
How it works — the formula
PMT = (FV − PV·(1+r)^n) · r / ((1+r)^n − 1)Solving the future-value-of-an-annuity equation for the periodic deposit (PMT) needed to reach a target FV from current balance PV in n periods at rate r. For monthly contributions r is the monthly rate (annual ÷ 12) and n is months. Match the compounding frequency to your contribution cadence to keep the math accurate.
Worked examples
- Inputs:
- goal = $80,000, current = $10,000, r = 4.5%/yr, t = 5 years
- Output:
- PMT ≈ $1,005/month
- Inputs:
- goal = $30,000, current = $0, r = 5%/yr, t = 3 years
- Output:
- PMT ≈ $774/month
- Inputs:
- goal = $120,000, current = $5,000, r = 6%/yr, t = 15 years
- Output:
- PMT ≈ $370/month
Limitations
- A constant rate is rarely realistic for goals over 5 years — equity and bond returns vary.
- Tax drag (interest on taxable savings) and account fees are not modeled.
- For tuition, healthcare, and housing the inflation rate routinely exceeds general CPI — bump the goal by 4–6%/yr in those categories.
- Withdrawal penalties on tax-advantaged accounts (e.g., 10% on 401(k) early withdrawals) are not accounted for.
Savings projections assume a constant return. This calculator does not provide financial advice — for goals tied to taxes (529, HSA, IRA), consult a CFP® professional or tax advisor.