Find out how much your savings will be worth. Enter a starting amount, a monthly contribution and an interest rate to see your future value and how much of it is interest.
Results
Future value
$106,639.02
After 10 years at 7%, your savings grow to $106,639.02, of which $36,639.02 is interest.
Total deposits
$70,000.00
Total interest earned
$36,639.02
Annual percentage yield (APY)
7.23%
DepositsInterest
Year-by-year breakdown
Year
Deposits
Interest
Balance
1
$16,000
$919
$16,919
2
$22,000
$2,339
$24,339
3
$28,000
$4,294
$32,294
4
$34,000
$6,825
$40,825
5
$40,000
$9,973
$49,973
6
$46,000
$13,782
$59,782
7
$52,000
$18,299
$70,299
8
$58,000
$23,578
$81,578
9
$64,000
$29,671
$93,671
10
$70,000
$36,639
$106,639
How this is calculated
The calculator simulates your account month by month.
Monthly rate. The annual rate r is compounded n times a year (1 = annually, 12 = monthly, 365 = daily). It is converted to the equivalent monthly rate i = (1 + r/n)^(n/12) − 1, so that twelve monthly steps produce exactly the same yearly growth as the chosen compounding frequency.
Each month the balance grows by i, and your contribution is added at the start or end of the month.
Totals. Total deposits are your initial deposit plus all monthly contributions; total interest is the future value minus total deposits.
For a single deposit with no contributions this is the classic formula A = P × (1 + r/n)^(n·t).
Worked example
You invest $10,000 and add $500 at the end of every month for 10 years at 7 % compounded monthly.
Your deposits add up to $10,000 + 120 × $500 = $70,000.
The future value is $106,639.02, so you earn $36,639.02 in interest.
The initial $10,000 on its own would have grown to $20,096.61; the monthly contributions account for the rest.
7 % compounded monthly equals an APY of about 7.23 %.
Compound interest is interest earned on both your original deposit and on the interest already added to your account. Because each period's interest is added to the balance, the balance grows faster every year than it would with simple interest.
What is the difference between APR and APY?+
The APR (annual percentage rate) is the nominal yearly rate before compounding. The APY (annual percentage yield) includes the effect of compounding within the year. For example, 7 % compounded monthly is an APY of about 7.23 %. Banks must quote APY on deposit accounts, so you can enter the bank's rate and choose annual compounding to reproduce it.
Does compounding frequency make a big difference?+
It matters, but much less than the rate and the time period. In the worked example below, monthly compounding earns $36,639 in interest against $35,197 with annual compounding, about 4 % more. Daily compounding adds less than 0.5 % on top of monthly.
Are taxes and inflation included?+
No. The calculator shows growth before taxes, fees and inflation. Interest on ordinary savings accounts is generally taxable as income, and inflation reduces what the final amount can buy.
Should I contribute at the start or the end of the month?+
Contributions at the start of each month earn one extra month of interest, so the result is slightly higher. Choose the option that matches when your deposits actually reach the account.
How long does it take to double my money?+
A quick estimate is the "rule of 72"; divide 72 by the annual rate. At 6 %, money doubles in about 12 years. Use the calculator with no monthly contribution for the exact figure.
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