Mortgage Calculator
Calculate monthly mortgage payments, total interest, and amortization schedule.
| Month | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $2,023 | $289 | $1,733 | $319,711 |
| 12 | $2,023 | $307 | $1,716 | $316,423 |
| 24 | $2,023 | $328 | $1,695 | $312,607 |
| 36 | $2,023 | $349 | $1,673 | $308,535 |
| 48 | $2,023 | $373 | $1,650 | $304,191 |
| 60 | $2,023 | $398 | $1,625 | $299,555 |
| 72 | $2,023 | $425 | $1,598 | $294,609 |
| 84 | $2,023 | $453 | $1,570 | $289,332 |
| 96 | $2,023 | $483 | $1,539 | $283,701 |
| 108 | $2,023 | $516 | $1,507 | $277,694 |
| 120 | $2,023 | $550 | $1,472 | $271,284 |
| 132 | $2,023 | $587 | $1,436 | $264,444 |
| 144 | $2,023 | $626 | $1,396 | $257,147 |
| 156 | $2,023 | $668 | $1,354 | $249,361 |
| 168 | $2,023 | $713 | $1,310 | $241,053 |
| 180 | $2,023 | $761 | $1,262 | $232,189 |
| 192 | $2,023 | $812 | $1,211 | $222,732 |
| 204 | $2,023 | $866 | $1,157 | $212,641 |
| 216 | $2,023 | $924 | $1,098 | $201,874 |
| 228 | $2,023 | $986 | $1,037 | $190,386 |
| 240 | $2,023 | $1,052 | $971 | $178,129 |
| 252 | $2,023 | $1,123 | $900 | $165,051 |
| 264 | $2,023 | $1,198 | $825 | $151,097 |
| 276 | $2,023 | $1,278 | $745 | $136,208 |
| 288 | $2,023 | $1,363 | $659 | $120,323 |
| 300 | $2,023 | $1,455 | $568 | $103,373 |
| 312 | $2,023 | $1,552 | $470 | $85,289 |
| 324 | $2,023 | $1,656 | $366 | $65,993 |
| 336 | $2,023 | $1,767 | $256 | $45,405 |
| 348 | $2,023 | $1,885 | $137 | $23,438 |
| 360 | $2,023 | $2,012 | $11 | $0 |
How Mortgage Payments Are Calculated
A fixed-rate mortgage uses the amortization formula:
M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the loan principal, r is the
monthly interest rate (annual rate divided by 12), and n is the total number of monthly
payments. Early payments go mostly toward interest; as the balance decreases, more of each
payment applies to principal.
The Impact of Down Payment Size
A 20% down payment on a $400,000 home ($80,000 down) eliminates private mortgage insurance (PMI), which typically costs 0.5%-1% of the loan annually. On a $320,000 loan, PMI adds $133-$267 per month. Putting down less than 20% is not disqualifying — FHA loans accept 3.5% down, and conventional loans go as low as 3% — but the extra monthly cost of PMI adds up over years.
15-Year vs 30-Year Mortgages
A 30-year term has lower monthly payments but costs significantly more in total interest. On a $320,000 loan at 6.5%, the 30-year option costs $407,000 in interest over the life of the loan. The 15-year option cuts that to roughly $182,000; a savings of $225,000, but monthly payments jump from $2,022 to $2,787. The right choice depends on your monthly cash flow and other investment opportunities. Use our Compound Interest Calculator to compare what that extra monthly payment could earn if invested instead.
Understanding Amortization
Amortization means the loan balance decreases with each payment according to a fixed schedule. In month one of a 30-year, $320,000 loan at 6.5%, about $1,733 of the $2,022 payment goes to interest and only $289 to principal. By month 180 (halfway through), the split is roughly $1,095 interest and $927 principal. The crossover point — where more goes to principal than interest — typically occurs around year 18-20 of a 30-year mortgage.
What This Calculator Does Not Include
Real mortgage costs include property taxes, homeowners insurance, PMI (if applicable), and HOA fees. These can add $500-$1,500+ per month depending on location. This calculator shows principal and interest only. For a full PITI (principal, interest, taxes, insurance) estimate, add those costs to the monthly payment shown here.
Frequently Asked Questions
- What interest rate should I use?
- Use the rate quoted by your lender, or check current average rates from Freddie Mac's Primary Mortgage Market Survey. Rates vary by credit score, down payment, loan type, and market conditions.
- Does this calculator include taxes and insurance?
- No. This shows principal and interest only. Property taxes, homeowners insurance, PMI, and HOA fees are additional costs that vary by property and location.
- How much home can I afford?
- The conventional guideline is that total housing costs (PITI) should not exceed 28% of gross monthly income. Adjust the home price and down payment in the calculator until the monthly payment fits your budget.