What is the compound interest formula?

A = P(1 + r/n)^(nt), where P is the starting amount, r is the yearly rate as a decimal, n is how many times a year interest is compounded and t is the number of years. Regular deposits are added with the future value of an annuity.

Does compounding more often make a big difference?

It helps, but not by much. At 5 percent, 10,000 grows to 16,288.95 over 10 years compounded yearly and 16,486.65 compounded daily. The rate and the number of years matter far more than the compounding frequency.

What is the effective yearly rate?

It is the rate you actually earn in a year once compounding is included. A 5 percent rate compounded monthly is an effective 5.12 percent, because interest is earned on interest during the year.

Does this include inflation, tax or fees?

No. It assumes a fixed rate and shows growth before tax, fees and inflation, so real returns will be lower. Use it to compare options and see the effect of time, not as a forecast.

Compound Interest Calculator

See how savings grow with compound interest and regular deposits, with a growth chart and year-by-year table.

Starting amount

Yearly interest rate (%)

Years

Compounded

Regular deposit

Optional. Use 0 for none.

Deposited

Deposit at the

Final balance: 144,572.72
Money put in: 58,000.00
Interest earned: 86,572.72
Effective yearly rate: 7.23%

Money put in Interest earnedHorizontal axis: year

Year	Deposits	Interest	Total put in	Total interest	Balance
1	2,400.00	801.42	12,400.00	801.42	13,201.42
2	2,400.00	1,032.85	14,800.00	1,834.27	16,634.27
3	2,400.00	1,281.01	17,200.00	3,115.28	20,315.28
4	2,400.00	1,547.11	19,600.00	4,662.39	24,262.39
5	2,400.00	1,832.45	22,000.00	6,494.83	28,494.83
6	2,400.00	2,138.41	24,400.00	8,633.24	33,033.24
7	2,400.00	2,466.49	26,800.00	11,099.74	37,899.74
8	2,400.00	2,818.29	29,200.00	13,918.03	43,118.03
9	2,400.00	3,195.52	31,600.00	17,113.55	48,713.55
10	2,400.00	3,600.02	34,000.00	20,713.58	54,713.58
11	2,400.00	4,033.77	36,400.00	24,747.34	61,147.34
12	2,400.00	4,498.86	38,800.00	29,246.20	68,046.20
13	2,400.00	4,997.58	41,200.00	34,243.79	75,443.79
14	2,400.00	5,532.35	43,600.00	39,776.14	83,376.14
15	2,400.00	6,105.79	46,000.00	45,881.93	91,881.93
16	2,400.00	6,720.67	48,400.00	52,602.60	101,002.60
17	2,400.00	7,380.00	50,800.00	59,982.60	110,782.60
18	2,400.00	8,087.00	53,200.00	68,069.60	121,269.60
19	2,400.00	8,845.11	55,600.00	76,914.70	132,514.70
20	2,400.00	9,658.02	58,000.00	86,572.72	144,572.72

Amounts are plain numbers, so use any currency. Results assume a fixed rate and no taxes or fees. Nothing you type leaves your browser.

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What is Compound Interest Calculator?

Compound interest is interest earned on interest. Each time interest is added to your balance, the next round of interest is worked out on the larger amount, so growth speeds up over time. It is why savings and investments that are left alone for years grow much faster than the same money earning simple interest, and why debt that is not paid off can grow so quickly.

This compound interest calculator shows what a starting amount grows to over a number of years at a yearly rate. Choose how often interest is compounded, from daily to yearly, and add a regular deposit every month or every year, paid at the start or the end of the period. It gives you the final balance, how much of it is money you put in and how much is interest, and the effective yearly rate once compounding is counted.

A bar chart splits each year’s balance into money put in and interest earned, so you can see the interest take over as time goes on, and a year-by-year table has the exact figures. The calculations follow the standard formula A = P(1 + r/n)^(nt) and the future value of a series of deposits. Amounts are plain numbers, so any currency works, and nothing you enter leaves your browser.

How to use

Enter the starting amount, the yearly interest rate and the number of years.
Choose how often the interest is compounded.
Add a regular deposit if you will keep saving, and choose monthly or yearly and the start or the end of the period.
Read the final balance, the money put in and the interest earned.
Use the chart and the year-by-year table to see how the balance grows.

Example

Input

10,000 at 5% for 10 years, compounded yearly, no deposits

Output

Final balance 16,288.95, of which 6,288.95 is interest

Frequently asked questions

What is the compound interest formula?: A = P(1 + r/n)^(nt), where P is the starting amount, r is the yearly rate as a decimal, n is how many times a year interest is compounded and t is the number of years. Regular deposits are added with the future value of an annuity.
Does compounding more often make a big difference?: It helps, but not by much. At 5 percent, 10,000 grows to 16,288.95 over 10 years compounded yearly and 16,486.65 compounded daily. The rate and the number of years matter far more than the compounding frequency.
What is the effective yearly rate?: It is the rate you actually earn in a year once compounding is included. A 5 percent rate compounded monthly is an effective 5.12 percent, because interest is earned on interest during the year.
Does this include inflation, tax or fees?: No. It assumes a fixed rate and shows growth before tax, fees and inflation, so real returns will be lower. Use it to compare options and see the effect of time, not as a forecast.