Mortgage Calculator
Your monthly mortgage payment — principal and interest only — with total cost over the life of the loan.
Inputs
Result
Visual breakdown
System view
See how this fits into your full financial system.
Zoom out and connect income, expenses, debt, savings, housing, transportation, and runway in one private system view.
Formula
Loan = price − down. Monthly = L × r × (1+r)n ÷ ((1+r)n − 1), where r = APR/12.
Example
$450k home, $90k down (loan $360k), 6.85% APR, 30 yr (360 payments) → $2,359/month; total interest ≈ $489k.
Related: Loan payment · Interest · Savings
How to use
- Enter the home price and your down payment.
- Enter the mortgage APR and term in years.
- Read the monthly principal & interest payment, plus the total interest.
- Add taxes, insurance, HOA and PMI separately to get full housing cost.
When it's useful
- Estimating monthly costs before house hunting.
- Comparing 15-year vs 30-year terms.
- Seeing how a bigger down payment changes the payment.
- Sanity-checking a lender's quote.
Common examples
Common answers
- How much is a $300,000 mortgage at 7%?≈ $1,996/mo principal & interest over 30 years.
- How much is a $500,000 mortgage at 6.5%?≈ $3,160/mo P&I over 30 years.
- How much does 1% interest change the payment?On a $300k loan over 30 years, ≈ $190–$200/mo per 1%.
- 15-year vs 30-year?A 15-year cuts total interest sharply but raises the monthly payment ~50%.
- What's actually in the payment?Principal and interest only here — taxes, insurance and PMI add on top.
- What happens if I pay extra each month?Use the Extra Mortgage Payment Calculator to see months saved and interest avoided.
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Frequently asked
Does this include taxes and insurance?
No — this is principal & interest only. Add property tax, insurance and HOA separately for a true monthly housing cost.
What does down payment percent affect?
A larger down payment lowers the loan amount (and monthly payment) and may help you avoid private mortgage insurance below 20%.
How does APR compare to interest rate?
APR includes lender fees in an annualized rate; the interest rate alone is lower. Use APR for an apples-to-apples cost comparison.
What is PMI?
Private mortgage insurance is required by most US lenders when you put down less than 20%. It protects the lender, not you, and adds to your monthly payment.
15-year vs 30-year mortgage?
15-year terms have higher monthly payments but a lower rate and far less total interest. 30-year terms are easier on cash flow.
Should I make extra principal payments?
Extra principal shortens the term and cuts total interest. Even one extra payment a year can save thousands.
People also calculate
More money & work →Estimates only. Real mortgages include taxes, insurance, fees and PMI — confirm with your lender before deciding.