Compound interest calculator with graph help


Settings Remark
Nominal interest rate (R) The nominal interest rate (R) is expressed as percentage (%) per year.

The interest rate may contain max two digits after its decimal point.
The interest rate entered may contain a comma (,) or point (.) as a decimal point separator.

Correct entered interest rates
5.25
5,25
4

Incorrect entered interest rates
5.041

The nominal interest rate (R) is specified per year. If the time period (T) is set to another unit than year for example weeks, the calculator will adjust the time period accordingly.

Example 1: How time period will be adjusted:
Interest rate = 5% per year
Time period = 7 weeks

52 weeks equals 1 year
Thus 7 weeks equals 7/52 = 0.1346 years

Example 2: How time period will be adjusted:
Interest rate = 5% per year
Time period = 2 quarters

4 quarters equals 1 year
Thus 2 quarters equals 2/4 = 0.5 year

Example 3: How time period will be adjusted:
Interest rate = 5% year
Time period = 5 bi-weeklies

26 bi-weeklies equals 1 year
Thus 5 bi-weeklies equals 5/26 = 0.1923 year

The compound interest equation:

R = N * ((FV / P)1 / (N * T)   - 1)

or

R = N * ((I / P) + 1)1 / (N * T)   - 1)

where:
FV = Future value
I = Interest amount
P = Principal initial amount
R = Nominal interest rate per year (as a decimal, not in percentage)
T = Time period in years
N = Number of compounding periods in one year