How to use it
- Enter your total loan amount after deducting your down payment.
- Input your expected annual interest rate.
- Select your loan term in years.
- Review your monthly payment, total interest, and total amount paid.
Buying a home is the largest debt you will ever take on. You cannot afford to guess what it costs. This calculator gives you absolute clarity on three critical metrics: your fixed monthly principal and interest payment, the total cash you will hand over to the bank, and the exact dollar amount of pure interest you will pay over the life of the loan.
A lower monthly payment over a longer term often blinds buyers to massive interest costs. Seeing the total interest alongside the monthly number allows you to weigh cash flow against long-term wealth destruction.
Use this tool to test multiple scenarios before talking to lenders. When you know your numbers upfront, you negotiate from strength, avoid borrowing past your limits, and choose the term length that actually serves your financial goals.
Pro tips
- Compare 15-year and 30-year terms side by side to see how much total interest you save.
- Remember that property taxes, homeowner's insurance, and PMI are not included in this base principal and interest figure.
- Even a 0.5% lower interest rate saves tens of thousands of dollars over the loan term—shop multiple lenders.
- Round your monthly payments up to the nearest hundred to silently shave years off your payoff timeline.
Real-life examples
- Evaluating whether to make a larger down payment to lower fixed monthly housing costs.
- Deciding between a 15-year and a 30-year fixed-rate mortgage for a new home purchase.
- Calculating the true long-term interest cost before refinancing an existing loan balance.
Case study
Marcus was pre-approved for a $400,000 mortgage over 30 years at 6.5%. By plugging his numbers into the calculator, he realized he would pay over $510,000 in interest alone. Shocked by the total cost, he tested a 20-year term, accepted a slightly higher monthly payment, and saved over $180,000 in interest while building home equity a decade faster.