How much to deposit each month to reach your savings goal

Begin with a picture of the future. You have a date in mind and an amount you want to see in the account. The job now is to choose a monthly deposit that will carry you there with room to breathe. That number is not a guess. It comes from a short list of inputs you already know: target amount, time until the deadline, expected rate, and your starting balance.

Two plans that actually work

The steady plan: pick a deposit you can keep every month without fail. This is the most reliable option for families and anyone juggling multiple goals. Progress may look slow in the early months, then it starts to bend upward as compounding builds on itself.

The aggressive plan: front load more in the first year, then settle into a lower amount after that. The early push gives your balance more time in the market and moves the finish line closer even if you taper later.

Both plans benefit from consistency. Missed months are more expensive than they look because you lose growth on the deposit and the growth on the growth.

Try it quickly with the calculator

Open the Savings Goal Calculator and plug in your target, timeline, starting balance, and estimated annual rate. Adjust the monthly deposit until the projection lands on your goal. If your timeline is flexible, try nudging the end date or rate to see which lever moves the result more comfortably. For curiosity, you can also simulate growth with the Compound Interest Calculator.

Common pitfalls

  • Ignoring compounding frequency when comparing accounts. The effective annual rate is the fairest yardstick.
  • Forgetting that deposits at the beginning of the period grow a bit more than deposits at the end.
  • Letting a missed month pass without a catch up plan. Add a one time top up or spread it across the next few months.

For the curious: the math

The monthly deposit that reaches a target in n months at rate i per month with starting balance PV is the payment from the standard future value relationship.

Payment formula: PMT = (FV - PV×(1+i)^n) × i / ((1+i)^n - 1)

Excel or Sheets example with 5 years, 4 percent annual, monthly compounding, and a 2,000 starting balance:

  • Monthly rate: =0.04/12
  • Periods: =5*12
  • Payment: =PMT(0.04/12, 5*12, -2000, 20000, 0)

The sign convention uses negatives for cash you contribute and a positive future value. Set type to 1 if you deposit at the beginning of each month.