# Principle and interest calculations [closed]

I have a loan at 5%, I know the total owed and the monthly payment and need aschedule giving me the interest and principle paid each month until paid in full. Where can i find a schedule calculator which will give me this breakdown.

• If you put your first sentence in google, you should fine something. Mar 11 '20 at 13:27
• Search for "amortization schedule calculator" Mar 11 '20 at 13:30

This is an alternative to setting up a chaining amortisation table.

Taking formulae and example figures from this answer: Loan balance for a specific month

Given

``````s = principal
i = periodic rate
m = number of periods
d = periodic payment

d = s * i * (1 + 1/((1 + i)^m - 1))
``````

the balance `b` remaining in month `x` is

``````b = (d + (1 + i)^x * (i * s - d))/i
``````

Applying example figures, with 10% nominal APR compounded monthly over 10 years

``````  s = 100000
i = 0.1/12
m = 10 * 12

∴ payment d = s * i * (1 + 1/((1 + i)^m - 1)) = 1321.51
``````

Balance in final month (120), should be zero

``````  x = 120
∴ balance b = (d + (1 + i)^x * (i * s - d))/i = 0
``````

Interest at the end of month `x`

``````interest = (d + (1 + i)^(x - 1) * (i * s - d))
``````

so interest at the end of month 1

``````  x = 1
∴ interest = (d + (1 + i)^(x - 1) * (i * s - d)) = 833.33

& principal paid = d - interest = 488.17
``````

At the end of month 2, etc.

``````  x = 2
∴ interest = (d + (1 + i)^(x - 1) * (i * s - d)) = 829.27

& principal paid = d - interest = 492.24
``````

... and so on, until at the end of the final month (120)

``````  x = 120
∴ interest = (d + (1 + i)^(x - 1) * (i * s - d)) = 10.92

& principal paid = d - interest = 1310.59
``````

The total interest is `m * d - s = 58580.88`

Demonstrated in Excel, showing formulas on the right. 