Mortgage & Loan Calculator: Free Online Payment & Amortization Tool
Estimate your monthly payment, total interest, and full amortization schedule. Private and free — runs entirely in your browser, no upload required.
Estimated monthly payment
$2,022.62
$2,022.62 principal & interest
$320,000
Loan amount
$408,142
Total interest
$728,142
Total cost of loan
Aug 2056
Payoff date
Monthly Payment Composition
- Principal & Interest
Amortization Schedule
| Year | Principal paid | Interest paid | Ending balance |
|---|---|---|---|
| ▸ Year 1 | $3,577 | $20,695 | $316,423 |
| ▸ Year 2 | $3,816 | $20,455 | $312,607 |
| ▸ Year 3 | $4,072 | $20,200 | $308,535 |
| ▸ Year 4 | $4,345 | $19,927 | $304,191 |
| ▸ Year 5 | $4,636 | $19,636 | $299,555 |
| ▸ Year 6 | $4,946 | $19,325 | $294,609 |
| ▸ Year 7 | $5,277 | $18,994 | $289,332 |
| ▸ Year 8 | $5,631 | $18,641 | $283,701 |
| ▸ Year 9 | $6,008 | $18,264 | $277,694 |
| ▸ Year 10 | $6,410 | $17,861 | $271,284 |
| ▸ Year 11 | $6,839 | $17,432 | $264,444 |
| ▸ Year 12 | $7,297 | $16,974 | $257,147 |
| ▸ Year 13 | $7,786 | $16,485 | $249,361 |
| ▸ Year 14 | $8,308 | $15,964 | $241,053 |
| ▸ Year 15 | $8,864 | $15,407 | $232,189 |
| ▸ Year 16 | $9,458 | $14,814 | $222,732 |
| ▸ Year 17 | $10,091 | $14,180 | $212,641 |
| ▸ Year 18 | $10,767 | $13,505 | $201,874 |
| ▸ Year 19 | $11,488 | $12,784 | $190,386 |
| ▸ Year 20 | $12,257 | $12,014 | $178,129 |
| ▸ Year 21 | $13,078 | $11,193 | $165,051 |
| ▸ Year 22 | $13,954 | $10,317 | $151,097 |
| ▸ Year 23 | $14,888 | $9,383 | $136,208 |
| ▸ Year 24 | $15,886 | $8,386 | $120,323 |
| ▸ Year 25 | $16,949 | $7,322 | $103,373 |
| ▸ Year 26 | $18,085 | $6,187 | $85,289 |
| ▸ Year 27 | $19,296 | $4,976 | $65,993 |
| ▸ Year 28 | $20,588 | $3,683 | $45,405 |
| ▸ Year 29 | $21,967 | $2,305 | $23,438 |
| ▸ Year 30 | $23,438 | $833 | $0 |
How This Calculator Works
Enter a home price, down payment, interest rate, and loan term, and this calculator builds a full amortization schedule in real time. The monthly principal & interest payment uses the standard amortization formula: M = 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 monthly payments. That formula produces a level payment that stays fixed for the life of the loan, even though the split between interest and principal shifts every month as the balance drops. Property tax, home insurance, and HOA dues are added on top as a flat monthly amount, since none of those change how the loan itself amortizes. Extra monthly payments go straight to principal, which shortens the payoff date and reduces total interest by removing balance that would otherwise keep accruing interest for years.
Reading the amortization schedule
The schedule groups payments by year and shows how much of that year's payments went to principal versus interest, along with your ending balance. Click a year to expand it into individual months, each with its own interest, principal, and remaining balance. Early in the loan, most of each payment covers interest because the balance is still close to the original loan amount. As the balance falls, more of each fixed payment chips away at principal, which is why the principal column grows and the interest column shrinks as you scroll toward the final years. This curve is steeper on a 30-year term than a 15-year term, because a longer term spreads the same loan amount over more months at a lower payment, which means the balance takes longer to fall and interest has more time to compound.
What extra payments actually do
Adding an extra monthly payment doesn't change your required monthly bill from the lender's perspective; it applies the surplus directly against the outstanding principal the moment it lands. Because interest is calculated on the remaining balance each month, a lower balance means less interest accrues the following month, which compounds over the life of the loan. Even a modest extra payment, applied consistently, can cut years off a 30-year term and remove tens of thousands of dollars in interest. The payoff date and total interest figures above update the instant you change the extra payment field, so you can experiment with different amounts and see the tradeoff without doing the math by hand.
Choosing between loan terms
A 15-year loan carries a higher monthly payment than a 30-year loan for the same amount, but a meaningfully lower interest rate is common and the total interest paid over the life of the loan is usually far smaller, since you're borrowing for half the time. A 30-year loan lowers the monthly commitment and frees up cash flow, at the cost of paying more in interest overall. Switching the term buttons above recalculates every figure on the page instantly, so you can compare a 30-year, 20-year, 15-year, or 10-year term side by side before deciding which monthly payment fits your budget.
Property tax, insurance, and HOA dues
Click "+ More options" to add annual property tax, annual home insurance, and monthly HOA dues to the estimate. These costs are common alongside a mortgage payment, and lenders often collect tax and insurance through an escrow account bundled into your monthly bill. The calculator divides annual figures by twelve and adds them to the base principal and interest payment, and the pie chart breaks down exactly how much of your total monthly payment goes to each category. Leaving these fields blank shows the pure loan payment on its own, which is useful when you're comparing loan offers rather than total cost of ownership.
Tips for accurate estimates
Use the interest rate quoted on a specific loan offer rather than a general market average, since even a quarter-point difference changes the total interest paid by thousands of dollars over a 30-year term. Set the start date to your expected closing month so the payoff date shown reflects reality rather than today's date. If you're comparing multiple properties, keep the term and rate fixed and vary only the price and down payment, so the comparison isolates the variable that actually changes between homes.
This is an estimate for planning purposes. Actual loan terms, taxes, insurance rates, and closing costs vary by lender and location. Nothing you enter is uploaded; every calculation runs locally in your browser.
Related: Freelance Rate Calculator for income planning, or Savings Goal Tracker for saving toward a down payment.
Frequently Asked Questions
Is the Mortgage Calculator free?
Yes — completely free. No account and no data sent to a server; every calculation runs locally in your browser.
Does this include property tax and insurance?
Yes, optionally. Click "+ More options" to add annual property tax, annual home insurance, and monthly HOA dues — they're added to the base principal & interest payment to show your full estimated monthly cost.
How do extra payments affect my loan?
Any amount entered as an extra monthly payment is applied directly to the loan principal each month, on top of the regular payment. This reduces the balance faster, which shortens the total loan term and lowers the total interest paid — the amortization schedule and payoff date update automatically.
Why is my total interest so much higher than the loan amount?
Interest compounds on the remaining balance every month over a long term (commonly 15–30 years), so even a moderate rate adds up. Early payments are mostly interest because the balance is still high; later payments are mostly principal — you can see this shift in the amortization schedule above.