Big expenses are easier when you break them into monthly amounts. This savings calculator works backward from a goal — an emergency fund, a down payment, a car or a trip — and tells you how much to set aside each month (and roughly each week) to get there on time, counting the interest your money earns along the way.
How to use the savings calculator
- Enter your goal — the amount you want to have.
- Enter what you've already saved toward it.
- Enter the time you have in years (1.5 for 18 months).
- Enter the interest rate your savings account pays, or 0 if the money sits in cash.
Savings goal formula
Monthly saving = amount still needed × i ÷ ((1 + i)^n − 1)
With no interest: monthly saving = amount still needed ÷ n
- i — monthly interest rate (annual rate ÷ 12)
- n — number of months
This is the standard sinking-fund formula: deposits at the end of each month, interest compounded monthly.
Worked example: a $20,000 down payment
- Goal: $20,000 in 3 years (36 months), starting from $0
- Monthly rate: 4% ÷ 12 = 0.3333%
- Monthly saving: 20,000 × 0.003333 ÷ (1.003333^36 − 1) = $523.81
- You deposit 36 × 523.81 = $18,857; interest supplies the other $1,143
Without interest you'd need $555.56 a month.
Monthly savings needed
Starting from $0, 4% interest compounded monthly.
| Goal | 1 year | 2 years | 3 years | 5 years |
|---|---|---|---|---|
| $5,000 | $409.08 | $200.46 | $130.95 | $75.42 |
| $10,000 | $818.17 | $400.92 | $261.91 | $150.83 |
| $25,000 | $2,045.41 | $1,002.29 | $654.77 | $377.08 |
| $50,000 | $4,090.83 | $2,004.58 | $1,309.53 | $754.16 |
Ways to hit your goal sooner
- Automate it. Schedule a transfer on payday so the money moves before you can spend it.
- Save raises and windfalls. Putting part of each pay raise or tax refund toward the goal speeds things up without cutting your current budget. See the Pay Raise Calculator.
- Shop the rate. High-yield savings accounts often pay several times more than standard accounts.
- Revisit the timeline. If the monthly figure is too high, extending the deadline by even six months can bring it down noticeably.
Choosing a realistic goal and timeline
Start with the number you actually need, not a round figure. For a down payment, check the percentage your lender requires and add closing costs. For a car, add taxes and registration to the sticker price. Then pick a deadline that fits your budget: if the calculator says $650 a month but you can comfortably set aside $450, stretch the timeline until the monthly amount fits, rather than planning to save more than you can. A goal you keep hitting each month builds momentum; one you keep missing usually gets abandoned.
Want to see how a balance grows instead? Use the Compound Interest Calculator. This calculator is for planning, not financial advice.
Frequently asked questions
How much do I need to save each month?
Without interest, divide the amount still needed by the number of months. $12,000 over 2 years is $500 a month. With interest, you need a little less each month because your balance earns money along the way.
How much should I save each month to have $20,000 in 3 years?
About $555.56 a month with no interest, or about $523.81 a month if the savings earn 4% compounded monthly.
Where should I keep savings for a short-term goal?
Goals a few years away are usually kept somewhere with little risk, such as a high-yield savings account, money market account or certificates of deposit. Money you may need soon is generally not invested in stocks, whose value can drop.
Should I include money I already have?
Yes. Enter it under “already saved”. It earns interest too, which lowers the monthly amount you need.
How big should an emergency fund be?
A common guideline is three to six months of essential expenses. Add up rent or mortgage, utilities, food, insurance, transportation and minimum debt payments, then use that total as your goal.