How to Calculate an Adjustable Mortgage

• 1). Gather all financial documents you have concerning your adjustable mortgage. You will need some of the figures included in this documentation when calculating your monthly mortgage payment.
  
  
• 2). Find current ARM (adjustable rate mortgage) interest rates. These rates can be found on your lender's website, financial forecasting websites and newspapers.
  
  
• 3). Use an online adjustable mortgage calculator to get the most accurate payment estimate.
  
  
• 4). Enter in the total loan amount, current adjustable mortgage rate and mortgage loan term. Other information you may need to enter includes the number of months before the first mortgage rate adjustment and the number of months between mortgage rate adjustments.
  
  
• 5). Use this payment estimate when creating monthly budgets or when refinancing.