Savings Goal Calculator
Set a savings goal and find the monthly deposit that will reach it in a given number of years, or find how long it takes with a deposit you choose. Enter what you have already saved and an expected interest rate, and see the interest earned along the way.
Savings goal calculator
How to use the savings goal calculator – monthly deposit and time to reach a goal
- Choose what to find. Pick "Monthly deposit needed" or "Time to reach the goal".
- Enter the goal and your savings. Type the target amount and what you have already saved.
- Enter the rate. Type the expected annual interest rate. Use 0 for none.
- Enter the time or the deposit. Type the years you have, or the monthly deposit you can afford, then read the result.
Formulas
Deposit = (goal − saved × gⁿ) × r ÷ (gⁿ − 1)
Months = ln((goal × r + d) ÷ (saved × r + d)) ÷ ln(1 + r)
where r is the monthly rate, g = 1 + r, n is the number of months and d is the monthly deposit.
Worked examples
Goal 20,000, saved 2,000, 4% a year, 5 years. You need 264.83 a month. Deposits total 15,889.84 and interest adds 2,110.16.
Same goal with 300 a month. The goal is reached in 54 months (4 years 6 months), with a balance of 20,111.03.
No interest. (20,000 − 2,000) ÷ 60 = 300 a month.
Setting a realistic goal
Start by writing the goal and the date, such as an emergency fund, a deposit or a holiday. Then compare the monthly amount with your budget. If it is too high, extend the time or reduce the goal. In the example above, stretching a 5-year plan to 6 years cuts the monthly deposit from 264.83 to 214.95, about a fifth less.
Saving versus investing
A savings account pays an interest rate that is usually stated and, up to deposit-protection limits, protected. Investments may grow faster, but returns are not guaranteed and value can fall, especially over short periods. If you need the money soon, a lower, safer rate is a better planning assumption. This calculator takes a single fixed rate and is not a forecast.
Related tools
To see how a lump sum plus monthly deposits grows, use the compound interest calculator. For one-off interest without compounding use the simple interest calculator, and to plan repayments on borrowing use the loan payment calculator. This tool provides general information, not financial advice.
Frequently asked questions
How do I work out how much to save each month?
Divide the gap by the number of months if there is no interest. With interest, use deposit = (goal − saved × g^n) × r ÷ (g^n − 1), where r is the monthly rate and g = 1 + r. A 20,000 goal with 2,000 saved at 4% over 5 years needs 264.83 a month.
How long will it take to reach my goal?
Enter a monthly deposit and the calculator counts the months. 300 a month towards the same goal at 4% takes 54 months, which is 4 years 6 months.
What if there is no interest?
Then the answer is simple division. (20,000 − 2,000) ÷ 60 months is 300 a month.
How much does interest help?
In the example, 15,889.84 of deposits earn 2,110.16 of interest. The longer the time and the higher the rate, the bigger the share that interest provides.
When are deposits made?
The calculator assumes a deposit at the end of each month with monthly compounding. Depositing at the start of the month would help slightly.
What rate should I use?
Use the rate offered by your savings account, which is guaranteed only as long as the bank says. Be cautious with investment returns, which are not guaranteed, and use a conservative figure.
Does inflation matter?
Yes. A goal that costs 20,000 today may cost more in five years. Increase the goal, or use a rate that is net of inflation, to plan for that.
Related calculators
Compound Interest Calculator – With Monthly Deposits
Ending balance with monthly deposits, any compounding, and the effective annual rate.
Simple Interest Calculator – Interest and Total Amount
Interest and total from principal, rate and time, in years, months or days.
Loan Payment Calculator – Monthly Payment, Interest and Payoff
Monthly payment, total interest and the effect of extra payments.
Tip Calculator – Tip, Total and Split the Bill
Tip, total and cost per person, with rounding and a quick percent table.
Sources and references
About this calculator
Written and maintained by Rashid Mehmood, founder of CalcTen. The formulas are unit-tested against hand-worked examples, and the content is reviewed whenever product sizes or guidance change. Last updated 14 November 2026. See our editorial policy.
This calculator gives general information and is not financial, tax or investment advice. It assumes a fixed rate and ignores fees, taxes and inflation, and real products differ. Check the terms with your bank or lender before making decisions. Read the disclaimer.