This is the Pro version of Karl's Mortgage Calculator. The only change from the free version is that the adverts have been removed. Calculate mortgage payments given principal, interest and term. Reverse calculate any one variable given the other three. Enter a down payment amount or percentage and let the calculator show how large a mortgage you require. See how the monthly payment changes when you factor in additional monthly or annual loan costs such as PMI, HOA, taxes and insurance. The calculator supports Fixed and Adjustable Rate Mortgages (ARM) loans with up to five changes in interest rates. Interest-only mortgages loans are also supported. You can pay off your mortgage early with extra payments. Add one-off, monthly and annual extra payments. Choose up to six additional extra payment amounts and payment periods and the calculator will show how much money you can save on the loan. Choose from weekly to annual loan payments and adjust the compounding period from daily through annual periods. The calculator supports Canadian mortgages along with UK annual rest mortgages. Multiple rounding options on loan calculations are also available. Choose between no rounding, round half up, half down, to even, to ceiling and to floor. The calculator also supports the input and display of multiple currencies.