The most advanced calculator for adjustable/variable rate mortgages

Understanding adjustable/variable rate mortgages (ARM) isn't easy. Our mortgage calculator is designed to help you understand the potential total principal and interest payments, as well as the minimum, average and maximum monthly payments, using different scenarios for the interest rate index. All this for FREE.

Note: The amortization schedule is computed using the full amortization method.

Calculate the variable/adjustable rate mortgage amortization plan

To use our calculator, enter the data on the left and click on "Calculate". On the right, you'll see four graphs: The interest rate scenario; the month-by-month payments (including payment total and principal repayment); the total paid interest versus principal comparison; and the minimum, average and maximum monthly payments. Point on each graph with your mouse to view the details.

About variable interest rate and the interest rate index

You can't simulate a variable/adjustable rate mortgage without a forecast for the interest rate index. Using futures contracts and historical data for a given index, it is possible to create a hypothesis (not to be confused with a prediction) to understand how much you could end up paying. You can find such hypoteses for USD, GBP and EURO LIBOR rates on this website.

These hypoteses are based on futures contracts for the first 6 years and on historical data for the subsequent period. The average scenario is based on pure futures contracts and historical data; the pessimistic scenario uses the same data but with an increment of 1% over the mortgage lifetime; and the optimistic scenario supposes a decrement of 1% over the same period.

You can also try and create your own custom scenarios. To do so, point your mouse pointer over the top interest rate graph and follow the instructions.


Visually compare different plans and scenarios

Mortgage calculator ³ allows you to simulate mortgages with different rates, different terms, as well as with or without a cap. You can visually compare different scenarios for the monthly payments and total amounts. To do so, save each calculated plan by clicking on the "Save" button. You will be prompted to create an account when saving your first plan - this is required for taking advantage of the comparison tool and registration is free. When you have at least two saved plans, select the first one you want to compare, press the "Compare" button, and then select another plan for the comparison.

Capped variable/adjustable rate mortgage

The risk of a variable/adjustable rate mortgage (ARM) can be reduced if there is a cap - a preset maximum - for the interest rate. Banks often require a higher spread to accompany this lower-risk option. In this case, if the variable rate is below the cap, the mortgage payment would typically be higher than with an uncapped ARM. On this website, you can simulate your mortgage payments with and without the cap to compare the two options across different scenarios.

Principal ($):
Term (years):
FPA Type:
Spread (%):
Rate (%):
N (years):
Cap (%):
Max + years:
Our advanced ARM calculator FREE on your website: Read more