# A.R.M. Comparison Calculator

### Help me compare adjustable rate mortgages with different terms.

Calculate and compare (formatted side by side) the monthly payments for up to 4 adjustable rate mortgage loans. The calculator has the interest rate always go up after the minimum length between steps and it always goes up the maximum step percent until the interest rate reaches the maximum. Therefore, this calculator is designed to show you the worst case scenario or maximum possible payout for an A.R.M., which is not likely to actually happen. Enter your sale price, any down payment you’re making, the initial fixed interest rate and the guaranteed fixed rate length, the maximum interest rate adjustment and the minimum length of time between adjustments, the maximum interest rate and the entire length of each loan. This calculator will then show you the initial fixed rate monthly principal and interest payment, your maximum monthly principal and interest payment, the total amount of interest you will pay and the total amount of money you will spend over the life of each loan. You can also enter the points and other closing costs and roll those into your loans. You can even enter an additional payment amount you intend to pay each month to work down your principal and the calculator will show you the anticipated payoff time.

## Field Help

### Input Fields

Title: A title for these calculator results that will help you identify it if you have printed out several versions of the calculator.

Lender: The name of your potential lender. This field is not required but may help if you have printed out several loan scenarios.

Sale Price: The sale price for your property. (NOT the amount of money you plan to borrow.)

Down Payment: The amount of money you plan to put as a down payment on your property.

Initial Interest Rate: The initial interest rate for your adjustable rate mortgage.

Length of Initial Fixed Rate: The length of time the ‘Initial Interest Rate’ is guaranteed or fixed. The ‘Length of Initial Fixed Rate’ is probably several years and is usually longer than the ‘Minimum Length Between Steps’. Also choose whether ‘Length of Initial Fixed Rate’ is years or months.

Maximum Interest Rate Step: The maximum percent your interest rate can go up each time it is adjusted.

Minimum Length Between Steps: Each interest rate adjustment will hold the new rate for at least this long. Also choose whether ‘Minimum Length Between Steps’ is years or months.

Maximum Interest Rate: Your interest rate cannot go higher than ‘Maximum Interest Rate’.

Length of Loan: How long you will pay on this loan. Also choose whether ‘Length of Loan’ is years or months.

Additional Principal: The additional amount you will pay each month (over the required monthly amount) to pay down the principal on your loan. While paying additional principal each month on a tradional mortgage has a significant effect on the payoff time, it does not have that same effect on the payoff time of an adjustable rate mortgage. That’s because each time the interest is adjusted the payment changes and is calculated on the balance at the time of adjustment spread over the remaining payoff time. Even though additional principal doesn’t pay an adjustable rate mortgage off a lot quicker, it does keep the payments more even between the high and low interest rate as it is adjusted.

Points: The number of points (or percentage of the loan amount) you’ll be paying to close this loan. Check ‘Roll into Loan’ if the cost of the loan points is being financed and included in the ‘Loan Amount’.

Other Closing Costs: Any other costs you’ll be paying during the closing of your loan. These might be costs like the appraisal, property taxes, property insurance, title insurance, realtor fees, etc. Check ‘Roll into Loan’ if your closing costs (not to include loan points) is being financed and included in the ‘Loan Amount’.

### Output Fields

Initial Payment: ‘Principal’ + ‘Interest’ + ‘Additional Principal’ (where applicable) to be paid each month. Actual payment could include escrow for insurance and property taxes plus private mortgage insurance (PMI).

Maximum Payment: ‘Principal’ + ‘Interest’ + ‘Additional Principal’ (where applicable) to be paid each month. Actual payment could include escrow for insurance and property taxes plus private mortgage insurance (PMI).

Average Payment: ‘Principal’ + ‘Interest’ + ‘Additional Principal’ (where applicable) to be paid each month. Actual payment could include escrow for insurance and property taxes plus private mortgage insurance (PMI).

Loan Amount: ‘Sale Price’ – ‘Down Payment’ + ‘Points’ (if rolled into loan) + ‘Other Closing Costs’ (if rolled into loan).

Maximum Total Interest: Total amount of interest you will pay over ‘Length of Loan’.

Maximum Total Paid: Total amount of principal + interest you will pay over ‘Length of Loan’.

Payoff Time: Amount of time until the loan is paid off.

Number of Payments: The number of payments you will make to pay off the loan.

Average Annual Cost: The amount of money you will pay each year for this loan.

Points Amount: The points percentage applied to the amount you borrow gives the dollar amount the loan points will cost.

Maximum Total Property Cost: Total cost of this property when you include the ‘Sale Price’, ‘Points Amount’, ‘Other Closing Costs’ and the ‘Total Interest’ to be paid on the mortgage.

### 2 thoughts on “A.R.M. Comparison Calculator”

1. Great Tool to use! Do you have a similar table for “Fixed” interest rate mortgages?