# Calculate mortgage rate with a different interest rate after certain years [closed]

I have a mortgage amount of 100K (\$100 000) and an Interest rate of 1.69% the first 2 years, then after the 9 years the Interest rate goes up to 8.9%. Payment frequency is monthly and the Amortization period is 19 years. What would be the new monthly payment amount? Thanks!

## closed as off-topic by Dheer, Pete B., Nathan L, BobbyScon, MD-TechJun 7 '18 at 9:15

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Questions about accounting are off-topic unless they relate directly to personal finance or investing from an individual's perspective." – Dheer, Pete B., Nathan L, BobbyScon, MD-Tech
If this question can be reworded to fit the rules in the help center, please edit the question.

• When is your homework due? If you already have a mortgage as you claim, the payment schedule will be spelled out for you already in the paperwork provided to you at the settlement, so look up the answer in your filing cabinet. – Dilip Sarwate Jun 2 '18 at 17:32
• Or try one of the HP-12C calculator applications on the web. – jamesqf Jun 2 '18 at 17:34
• Your question has stopped making any sense after the edit (is it 2 or 9 years ?). – xyious Jun 4 '18 at 17:01

## 1 Answer

With

``````s = principal
r = monthly interest rate
n = number of months
d = monthly payment

s = 300000
r = 2.95/100/12
n = 25*12
``````

Payment amount to pay off at 2.95% over 25 years

``````d = r (1 + 1/((1 + r)^n - 1)) s = 1414.84
``````

However, this is only maintained for four years.

Principal remaining after four years

``````x = 4*12
s = (d + (1 + r)^x (r s - d))/r = 265536.39
``````

Continuing with new figures.

``````r = 4.5/100/12
n = 21*12
``````

Payment amount to pay off at 4.5% over 21 years

``````d = r (1 + 1/((1 + r)^n - 1)) s = 1630.70
``````