Compound interest calculator
Enter a starting balance, a monthly deposit and a rate, and see your money grow year by year — with daily, monthly or yearly compounding.
Last updated:
What you put in Interest
| Year | You put in | Interest | Balance |
|---|---|---|---|
| 1 | $16,000 | $454 | $16,454 |
| 2 | $22,000 | $1,137 | $23,137 |
| 3 | $28,000 | $2,058 | $30,058 |
| 4 | $34,000 | $3,226 | $37,226 |
| 5 | $40,000 | $4,650 | $44,650 |
| 6 | $46,000 | $6,337 | $52,337 |
| 7 | $52,000 | $8,299 | $60,299 |
| 8 | $58,000 | $10,544 | $68,544 |
| 9 | $64,000 | $13,082 | $77,082 |
| 10 | $70,000 | $15,925 | $85,925 |
Deposits are added at the end of each month. With the ACK card your entire balance earns 3–4% APY, every day.
How compound interest works
Compound interest is interest on your interest. Each time interest is added to your balance, the next interest is worked out on the bigger balance — so growth speeds up over time.
The formula is A = P × (1 + r/n)n×t, where P is the starting balance, r the yearly rate, n how many times a year interest compounds, and t the number of years. This calculator adds your monthly deposits at the end of each month.
An example
$10,000 at 3.5% compounded daily grows to $14,190 in 10 years with no deposits. Add $500 a month and it grows to $85,925 — $70,000 of your money plus $15,925 of interest.
With the ACK card your entire balance earns 3–4% APY, every day. How it works
Questions
Is daily compounding better than monthly?
Slightly. At 3.5% for one year, $10,000 earns $356.18 with daily compounding and $355.67 with monthly compounding.
What is the difference between the interest rate and APY?
The interest rate doesn’t include compounding; APY does. What is APY?