Mortgage Calculator
This free mortgage calculator breaks down your monthly payment into principal, interest, taxes, and insurance (PITI). See exactly how much of each payment goes toward building equity vs. paying interest — and how extra payments can save you tens of thousands over the life of your loan.
Whether you're a first-time homebuyer comparing rates, deciding between a 15-year and 30-year mortgage, or planning your path to FIRE, this calculator gives you the full picture of your home financing costs.
A $320,000 mortgage at 6.5% for 30 years = $2,023/month P&I ($2,481 with tax & insurance). Over the life of the loan, you'll pay $408,142 in interest — that's 56.1% of total payments.
Formula: M = P × [r(1+r)n] / [(1+r)n - 1], where P = $320,000, r = 0.5417/mo, n = 360 payments
Loan details
20.0% down. 20%+ avoids PMI.
Current 30-yr fixed: ~6.5% (2026)
Typically 0.5–2.5% of home value
Results
Monthly Payment (PITI)
$2,481
P&I: $2,023 + Tax: $333 + Insurance: $125
Loan amount
$320,000
Total interest paid
$408,142
Total cost of loan
$728,142
Amortization schedule
Yearly breakdown of principal vs interest. Early years are mostly interest; later years shift to principal.
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | $3,577 | $20,695 | $316,423 |
| 2 | $3,577 | $20,695 | $316,423 |
| 3 | $3,577 | $20,695 | $316,423 |
| 4 | $3,577 | $20,695 | $316,423 |
| 5 | $3,577 | $20,695 | $316,423 |
| 10 | $3,577 | $20,695 | $316,423 |
| 15 | $3,577 | $20,695 | $316,423 |
| 20 | $3,577 | $20,695 | $316,423 |
| 25 | $3,577 | $20,695 | $316,423 |
| 30 | $3,577 | $20,695 | $316,423 |
How to use this calculator
Home price — The total purchase price of the property. This determines your loan amount after subtracting the down payment.
Down payment — Cash you pay upfront. Putting down 20% or more eliminates Private Mortgage Insurance (PMI), which typically costs 0.5–1.5% of the loan per year. For a $400K home, 20% down = $80K. FHA loans allow as little as 3.5% down.
Interest rate — Your annual percentage rate (APR). As of 2026, 30-year fixed rates are around 6.5%. A 0.5% rate difference on a $320K loan changes your payment by ~$100/month and total interest by ~$35K.
Loan term — 30 years is standard. A 15-year mortgage has higher monthly payments but saves dramatically on interest. On a $320K loan at 6.5%: 30-year = $2,022/mo ($408K total interest); 15-year = $2,789/mo ($182K total interest). That's $226K saved.
Property tax & insurance — These are escrowed into your monthly payment. Property tax varies widely by location (0.5% in Hawaii to 2.5% in New Jersey). Insurance averages $1,500–2,500/year nationally.
Real-world examples
Maria: First-time buyer with 5% down
Maria buys a $350,000 condo with 5% down ($17,500). Her loan: $332,500 at 6.5% for 30 years. P&I = $2,100/month. With $3,500/yr tax and $1,200/yr insurance, her total PITI = $2,475/month. Over 30 years, she pays $424K in interest — more than the loan itself. PMI adds another ~$170/month until she reaches 20% equity.
James & Sarah: 15-year vs 30-year decision
They're buying a $500K home with 20% down ($100K). Loan: $400K at 6.0%. 30-year: $2,398/mo P&I, $463K total interest. 15-year: $3,375/mo P&I, $207K total interest. The 15-year saves $256K in interest but costs $977/month more. They choose the 30-year and invest the difference — if their investments return 7%, they come out ahead.
The 0.5% rate difference
On a $320,000 loan for 30 years: at 6.0%, monthly P&I = $1,919 and total interest = $370K. At 6.5%, it's $2,022/mo and $408K in interest. That 0.5% difference costs an extra$103/month and $38K over the life of the loan. Shopping for the best rate is one of the highest-ROI activities in homebuying.
Formula & Methodology
Monthly payment formula
- M = Monthly principal & interest payment
- P = Loan principal (home price - down payment)
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (years × 12)
Assumptions & limitations
- Fixed-rate mortgage only. Adjustable-rate mortgages (ARMs) will have different payment schedules after the fixed period.
- PMI is not included. If your down payment is below 20%, add 0.5–1.5% of the loan amount per year.
- HOA fees, if applicable, are not included in the PITI calculation.
- Property tax and insurance are assumed constant. In reality, they increase over time.
Data sources
- Mortgage rates: Freddie Mac Primary Mortgage Market Survey (2026)
- Property tax rates: Tax Foundation, state-by-state data
- Insurance premiums: NAIC national averages