Compound Interest Calculator
How savings grow with compound interest, with regular deposits, any compounding frequency and a yearly table.
Your savings
Filled in with example values. Replace them with your own.
Interest is compounded
Regular deposits
Currency symbol
Results update as you type.
Result
$47,526.55 after 10 years: $34,000.00 paid in + $13,526.55 interest (5% compounded monthly)
After 10 years
$47,526.55
- Interest earned
- $13,526.55
- Total paid inStarting amount + deposits
- $34,000.00
- Effective annual rate5% compounded monthly
- 5.116%
What the balance is made of
- Starting amount
- $10,000.00
- Deposits
- $24,000.00
- Interest
- $13,526.55
- Final balance
- $47,526.55
Year by year
| Year | Paid in | Interest | Balance |
|---|---|---|---|
| 1 | $12,400.00 | $567.39 | $12,967.39 |
| 2 | $14,800.00 | $1,286.60 | $16,086.60 |
| 3 | $17,200.00 | $2,165.39 | $19,365.39 |
| 4 | $19,600.00 | $3,211.93 | $22,811.93 |
| 5 | $22,000.00 | $4,434.80 | $26,434.80 |
| 6 | $24,400.00 | $5,843.03 | $30,243.03 |
| 10 | $34,000.00 | $13,526.55 | $47,526.55 |
How it’s calculated
Growth each year
(1 + 5% ÷ 12)^12 = 1.05×
Starting amount grows to
$10,000.00 × growth^10 = $16,470.09
Deposits grow to
each deposit grows from the day it is made = $31,056.46
How the compound interest calculator works
With compound interest, the interest you earn is added to the balance and earns interest itself. The calculator grows your starting amount at the rate you enter, compounded as often as you choose, and adds any regular deposits, each growing from the time it is made.
Deposits are made at the end of each month or year. When deposits and compounding happen at different intervals, each deposit grows at the equivalent rate for its own period, so the result stays consistent.
The formula
A = P × (1 + r ÷ n)^(n × t)
Effective annual rate = (1 + r ÷ n)^n − 1
Deposits = D × ((1 + g)^k − 1) ÷ g
P is the starting amount, r the yearly rate, n the number of times interest is added each year and t the years. For deposits, D is each deposit, k the number of deposits and g the growth per deposit period.
Worked example
10,000 at 5% a year, compounded monthly, for 10 years:
- 10,000 × (1 + 0.05 ÷ 12)^120 = 16,470.09, so 6,470.09 is interest
- Effective annual rate: (1 + 0.05 ÷ 12)^12 − 1 = 5.116%
Adding 200 at the end of every month as well brings the balance to 47,526.55: 34,000 paid in and 13,526.55 of interest.
Assumptions and limitations
- The rate stays the same for the whole period.
- Deposits are made at the end of each period, in the same amount every time.
- Fees, taxes and inflation are not included.
Frequently asked questions
What is the effective annual rate?
It is what the rate is really worth over a year once compounding is included, sometimes called APY or AER. 5% compounded monthly grows money by about 5.116% a year, because each month’s interest earns interest too.
How much does compounding frequency matter?
More often is better, but the difference shrinks quickly. Over 10 years, 10,000 at 5% grows to 16,288.95 compounded yearly, 16,470.09 monthly and 16,486.65 daily.
How long does it take money to double?
A quick estimate is 72 divided by the rate: at 5%, about 14.4 years. The exact figure with yearly compounding is 14.2 years. The calculator shows the real balance for any period you enter.
Does the result include tax or inflation?
No. Interest may be taxable where you live, and inflation reduces what the final amount will buy. Both depend on your situation, so they are left out.