Put the mortgage amount in this box.
For example, if the mortgage amount is $150000, put 150000 without the dollar sign in the box.

Next, put in this box the annual interest rate.
If the interest rate is 5.25% put 5.25 in the box without the % sign.

Choose how often you will make payments. monthly every 2 weeks weekly

Next, choose the number of years for the amortization period.

Choose what country you live in. United States Canada

And click this button.

The total amount paid is:

The total interest paid is:

You can do this again with different numbers. Just hit the clear button.