Arm Mortgage Calculator
Calculate monthly payments and total cost for an Adjustable-Rate Mortgage (ARM). Input loan details and interest rate adjustments to see how payments change over time.
Published by:
isCalculator Editorial Team
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How to use this tool?
This calculator estimates monthly payments and total costs for an Adjustable-Rate Mortgage (ARM). Follow these steps:
- Enter Loan Amount ($) – The total mortgage principal.
- Enter Initial Interest Rate (%) – The fixed rate for the first period.
- Enter Initial Fixed Period (years) – How long the initial rate stays fixed.
- Enter Loan Term (years) – Total repayment period (e.g., 30).
- Enter Rate Adjustment per Period (%) – How much the rate changes each adjustment.
- Enter Adjustment Frequency (years) – How often the rate adjusts after the fixed period.
- Enter Maximum Rate (%) – The highest possible rate.
- Enter Minimum Rate (%) – The lowest possible rate.
- Click Calculate to see results.
Results show:
- Initial Monthly Payment (first payment)
- Final Monthly Payment (last payment)
- Total Interest Paid
- Total Cost (principal + interest)
- Yearly payment schedule with rate changes
Note: All rates are annual percentages. The calculator assumes monthly compounding and payments. Ensure the initial fixed period does not exceed the loan term.
Previous Results
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Frequently Asked Questions
An ARM (Adjustable-Rate Mortgage) has an interest rate that may change periodically based on market conditions. It typically starts with a lower fixed rate for a set period, then adjusts at predetermined intervals.
The monthly payment is calculated using the standard amortization formula for each rate period. During the fixed period, the rate is constant. After that, the rate adjusts according to the specified adjustment frequency, subject to caps.
Rate caps limit how much the interest rate can increase or decrease over the life of the loan. This calculator uses the maximum and minimum rates you input as absolute caps.
