**Old Loan:**

Rate = 4.375%

30 Year paying at 15 years (Prepay extra $500 in principal monthly to end 04/2032; note - loan originated 07/2017 and we started prepaying 1 year ago; I plugged the numbers into an amortization calculator factoring this in)

Current Monthly Payment = $844 + $500 = $1344

Original Principal = $169,600

Current Principal = $157,200

Interest Already Paid = $15,000

Remaining Interest = $48,000

Total

**Remaining**Cost of Loan = $48,000 + $157,200 = $205,000

**New Potential Loan:**

Rate = 3.25%

15 Year (Prepay extra $151 per month to end the loan at the same date of 04/2032; calculated using Excel amortization template)

Monthly Payment = $1104 + $151 = $1255

Current Principal = $157,200

Interest = $35,099

Closing Costs = ~$3500

Total Cost of New Loan = $35,099 + $157,200 + $3500 = $195,799

Monthly Payment Savings = 1344 - 1255 = $89 per month; $89 * 154 remaining payments = $13,706

**Final Total Cost = $195,799 - $13,706 = $182,093**

So by my calculations, if I stay with the original loan and continue to prepay and finish by 04/2032, the remaining cost is $205,000. Note, I am not counting the interest I have already paid on the current loan as this is a sunk cost (the $15K). The analysis is only about the remaining cost of each option.

If I refinance, the total cost is $182,093 which is a $23,093 (~150/month for 154 payments) savings over the 14 remaining years of the loan.

Did I do my math correctly?