Buying a home is probably the biggest financial decision you’ll ever make. The difference between a 6% and a 7% interest rate might not sound like much, but over 30 years it can mean tens of thousands of dollars. This calculator gives you the full picture before you sign anything: your monthly payment, total interest paid, and what the loan actually costs you from start to finish.

How to Use This Calculator

Step 1: Enter the price of the home you’re considering. If you’re still browsing, try a few different price points to see what each one costs per month.

Step 2: Enter your down payment amount. The more you put down, the lower your monthly payment and the less interest you pay over the life of the loan.

Step 3: Input the interest rate. Check current mortgage rates from your bank or a site like Bankrate or Freddie Mac to get a realistic number.

Step 4: Choose your loan term. 30 years gives you lower monthly payments but more total interest. 15 years costs more per month but saves you a massive amount in interest.

Step 5: Add your estimated annual property tax and homeowners insurance. These are often rolled into your monthly mortgage payment through escrow, so they matter for your real monthly cost.

30 Year vs 15 Year Mortgage: What the Numbers Actually Show

People default to 30 year mortgages because the monthly payment is lower. And that makes sense if cash flow is tight. But the total cost difference is staggering.

On a $280,000 loan at 6.5%, a 30 year mortgage costs you about $357,000 in interest over the full term. That same loan on a 15 year term costs roughly $151,000 in interest. That’s a difference of over $200,000. The monthly payment is higher with 15 years, obviously, but if you can afford it, the long term savings are hard to ignore.

Run both scenarios in the calculator above. Seeing your own numbers side by side makes the decision much clearer.

How Much House Can You Actually Afford

Lenders will approve you for more than you should probably spend. Just because a bank says you qualify for a $500,000 mortgage doesn’t mean your budget can handle it comfortably.

A common guideline is to keep your total housing costs, including principal, interest, taxes, and insurance, under 28% of your gross monthly income. Some people stretch to 30% or 33%, but the further you go, the less room you have for everything else: savings, retirement, emergencies, and actually enjoying your life.

Use this calculator to find a monthly payment that leaves you breathing room. Your future self will thank you.

Why Your Down Payment Size Matters More Than You Think

A larger down payment reduces your loan amount, which reduces both your monthly payment and the total interest you pay. If you put down less than 20%, most conventional loans also require private mortgage insurance (PMI), which adds another $100 to $300 per month that provides zero benefit to you. It protects the lender, not you.

Saving for 20% down is hard, and it’s not always realistic. But even the difference between 5% and 10% down can save you thousands over the life of the loan.