- ipmt(rate, per, nper, pv, fv?, when?): number
#### Parameters

- rate: number
Rate of interest as decimal (not per cent) per period

- per: number
Interest paid against the loan changes during the life or the loan. The

`per`

is the payment period to calculate the interest amount - nper: number
Number of compounding periods

- pv: number
Present value

- fv: number = 0
Future value

- when: PaymentDueTime = PaymentDueTime.End
When payments are due

#### Returns number

Interest portion of payment

#### Since

v0.0.12

## Examples

What is the amortization schedule for a 1 year loan of $2500 at 8.24% interest per year compounded monthly?

`const principal = 2500`

const periods = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

const ipmts = periods.map((per) => f.ipmt(0.0824 / 12, per, 1 * 12, principal))

expect(ipmts).toEqual([

-17.166666666666668,

-15.789337457350777,

-14.402550587464257,

-13.006241114404524,

-11.600343649629737,

-10.18479235559687,

-8.759520942678298,

-7.324462666057678,

-5.879550322604295,

-4.424716247725826,

-2.9598923121998877,

-1.4850099189833388

])

const interestpd = ipmts.reduce((a, b) => a + b, 0)

expect(interestpd).toBeCloseTo(-112.98308424136215, 6)The

`periods`

variable represents the periods of the loan. Remember that financial equations start the period count at 1!## Notes

The total payment is made up of payment against principal plus interest.

`pmt = ppmt + ipmt`

- rate: number

Generated using TypeDoc

Compute the interest portion of a payment.