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Mortgage Calculator | Compare Monthly Payments

This calculator compares monthly payments, interest cost and balance at maturity for different mortgages. It also stress-tests your future payments to ensure continued affordability if interest rates rise.

Mortgage 1 Mortgage 2 Mortgage 3
Amount
Term (Years)
Rate
Amortization
Compounding
Over Your First Term
Payment
Interest Paid
Balance at Maturity
Total Cost Difference
Over Your Total Amortization
Interest Paid
Payments At Renewal
If Rates Rise 2%-pts
If Rates Rise 3%-pts
* All figures rounded to the nearest dollar

Calculator Tips:

  • Payments & Balance:  When comparing two or more mortgages, you not only need to consider the payment difference but also the balance at the end of the term. This mortgage calculator factors in both when assessing the “Total Cost Difference” of up to three mortgages.
  • Prepayments Reduce Amortization: The longer your amortization (repayment period), the lower your payments. Remember, however, that most lenders allow prepayments. These are extra payments that decrease your principal dollar-for-dollar. As a result, each prepayment you make reduces your effective amortization.
  • Interest Rule of Thumb: On a new 25-year mortgage, you’ll pay more principal than interest on your very first payment, as long as your interest rate is below 2.80%.
  • Add Insurance: If you have less than 20% equity (down payment) you will generally need to purchase default insurance. If so, don’t forget to add insurance premiums to the mortgage amount. For example:  With 5% down, a $300,000 mortgage is 3.60% higher including insurance, or $310,800.
  • Stress Test Your Payments: Be honest about whether your budget can handle higher payments. If rates shoot up 3% in the next five years, this calculator will tell you what your new payment will be. And yes, it factors in your reduced balance and amortization at renewal.
  • Assumptions: These balance and interest figures assume no change in interest rates over the entire term and amortization period. In reality, rates can and do change. For one thing, you’ll typically renegotiate your rate at the end of each mortgage term. At that time, rates will be higher or lower. In addition, if you have a variable mortgage, your interest rate and payment may change as prime rate rises and falls.

Note: This calculator uses rounding for simplicity. It is not intended to be precise to the penny.