Mortgage Calculator
The Mortgage Calculator estimates your monthly principal and interest payment based on home price, down payment, interest rate, and loan term, with optional fields for property tax, insurance, and HOA dues. If you enter a 0% interest rate, the calculator switches to simple division (loan amount ÷ number of months) since the standard amortization formula would otherwise divide by zero. The tool floors the loan amount at $0 if your down payment ever exceeds the home price, and it computes principal & interest only — property tax and insurance are added on top as flat monthly figures rather than recalculated as your home's assessed value changes over time. Because it applies one constant rate across the full term, treat the result as valid only for the fixed-rate period of an ARM, not its entire life.
How This Tool Works
Enter your home price, down payment, interest rate, and loan term. Optionally add annual property tax, insurance, and monthly HOA dues for a complete monthly payment estimate.
Formula & Method
Monthly principal & interest = P × r × (1+r)^n ÷ ((1+r)^n − 1), where P is the loan amount, r is the monthly interest rate, and n is the number of payments.
Example Calculation
A $350,000 home with a $70,000 down payment leaves a $280,000 loan amount. Step 1: convert the annual rate to a monthly rate — 6.5% ÷ 12 = 0.541667% (0.00541667 as a decimal). Step 2: raise (1 + monthly rate) to the power of the total number of payments — (1.00541667)^360 ≈ 6.99180. Step 3: apply the amortization formula — M = 280,000 × 0.00541667 × 6.99180 ÷ (6.99180 − 1) = $1,769.79/month, which rounds to about $1,770/month in principal & interest. Step 4: multiply by 360 payments for total paid — $1,769.79 × 360 = $637,124.57. Step 5: subtract the loan amount for total interest — $637,124.57 − $280,000 = $357,124.57, meaning you'd pay more in interest than the original loan amount over the full 30 years.
Frequently Asked Questions
Does this include property taxes and insurance?+
Yes, if you fill in the optional annual tax and insurance fields, they're added to your monthly principal & interest payment for a full PITI estimate.
What interest rate should I use?+
Use current rates for your credit profile and loan type — check with a few lenders, since rates vary based on credit score, loan type, and market conditions.
Does a bigger down payment always help?+
A larger down payment reduces your loan amount and monthly payment, and can help you avoid private mortgage insurance (PMI) if it reaches 20% of the home price.
Does the calculator account for PMI (private mortgage insurance)?+
No — the annual insurance field is meant for homeowners insurance, not PMI. If your down payment is below 20% of the home price, lenders typically require PMI, which usually runs about 0.5%–1.5% of the loan amount per year; add that amount into the annual insurance field yourself if you want it reflected in your total monthly payment.
What happens if my down payment is larger than the home price?+
The loan amount can't go negative — the calculator caps it at $0 in that case, which would show principal & interest as $0/month. That's an edge case built in as a safeguard, and seeing a $0 payment is a sign to double-check your home price and down payment entries rather than an actual all-cash purchase result.
Found this useful? Share it
Help someone else out — or link to it from your own site.
Link to this tool
Writing about mortgage calculator? Paste this on your site to link here.
<a href="https://everyfix.net/tools/mortgage-calculator/">Mortgage Calculator</a> by <a href="https://everyfix.net">EveryFix</a>Related Tools
Loan Payment Calculator
Calculate the monthly payment for any fixed-rate loan.
Use tool →
Debt-to-Income Ratio Calculator
Calculate your debt-to-income ratio, a key number lenders check.
Use tool →
Auto Loan Calculator
Calculate your monthly car payment including tax, trade-in, and down payment.
Use tool →
Credit Card Payoff Calculator
See how long it will take to pay off a credit card balance.
Use tool →