Loan & Mortgage Amortization Estimator
Calculate the monthly payment on a mortgage or car loan, see total interest over the term, and get a full year-by-year amortization schedule you can download as CSV.
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Amortization Schedule (by year)
| Year | Principal Paid | Interest Paid | Remaining Balance |
|---|---|---|---|
| 1 | $6,623 | $8,085 | $143,377 |
| 2 | $6,996 | $7,711 | $136,381 |
| 3 | $7,391 | $7,316 | $128,990 |
| 4 | $7,808 | $6,900 | $121,182 |
| 5 | $8,248 | $6,459 | $112,933 |
| 6 | $8,714 | $5,994 | $104,220 |
| 7 | $9,205 | $5,502 | $95,015 |
| 8 | $9,724 | $4,983 | $85,290 |
| 9 | $10,273 | $4,435 | $75,017 |
| 10 | $10,852 | $3,855 | $64,165 |
| 11 | $11,465 | $3,243 | $52,700 |
| 12 | $12,111 | $2,596 | $40,589 |
| 13 | $12,794 | $1,913 | $27,795 |
| 14 | $13,516 | $1,191 | $14,279 |
| 15 | $14,279 | $429 | $0 |
Each year sums 12 monthly payments. Download the CSV for the full month-by-month breakdown.
Disclaimer: This free tool is provided “as is,” without warranties of any kind, and is for general informational purposes only — not professional, legal, financial, medical, tax, or engineering advice. Results may contain errors; verify anything important independently and use at your own risk. We accept no liability for any loss or damage arising from its use. See our Terms of Use for details.
Step-by-Step Guide
Set the loan principal (the amount you are borrowing), the annual interest rate, and the loan term in years. The monthly payment, total repayment, and total interest update immediately. Scroll down to see the year-by-year amortization table showing principal paid, interest paid, and remaining balance for each year of the loan. Click Download CSV to get the complete month-by-month schedule with every row calculated.
How the monthly payment is calculated
The fixed monthly payment is determined by the standard amortization formula: P = L × [r(1+r)^n] / [(1+r)^n − 1], where L is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (years × 12). This formula produces a payment that stays constant over the entire term while the proportion going to principal gradually increases and the interest portion decreases.
Reading the amortization table
In the early years of a long-term loan, most of each payment goes to interest rather than principal. On a 30-year mortgage at 6%, roughly 80% of the first payment is interest. This reverses gradually: by the final years, nearly all of each payment is principal. The table makes this visible — you can see exactly when you cross the point where more than half of each payment reduces the balance. This is also why making extra principal payments early in a loan's life has an outsized effect on total interest paid.
$150,000 at 5.5% over 15 years: the standard amortization formula gives a monthly payment of $1,225.63. Over 180 payments the total repaid is $220,613, meaning $70,613 is paid in interest — about 47% of the original loan. The year-1 row of the amortization table shows roughly $8,250 in interest and only $6,457 in principal; by year 15 those proportions are almost completely reversed.
Who it's for
Home buyers, real estate agents, automobile purchasers, and personal finance advisers.
Core Features
- Sliders for loan principal, annual interest rate, and term in years.
- Monthly payment, total repayment, and total interest over the life of the loan.
- Full amortization schedule summarized year-by-year (principal, interest, remaining balance).
- Download the complete month-by-month schedule as a CSV file.
🛡️ No tracking — your inputs, keys, and details never leave this client sandbox.
How is my monthly mortgage payment calculated?
It uses the standard amortization formula: the payment that pays off the loan over the full term at the given rate. Enter the loan amount, annual interest rate, and term in years and the monthly payment updates instantly, along with the total interest you'll pay over the life of the loan.
What is an amortization schedule?
It's the month-by-month (here summarized year-by-year) breakdown of how each payment splits between interest and principal. Early payments are mostly interest; over time more goes to principal. The table shows the principal paid, interest paid, and remaining balance for each year.
Can I export the full payment schedule?
Yes. Download CSV gives you every single month — payment, principal portion, interest portion, and remaining balance — which you can open in Excel or Google Sheets. A 15-year loan exports as 180 monthly rows.
How much will I pay in interest overall?
The result panel shows total interest as a dollar figure and as a share of your total repayment, with a bar splitting principal versus interest — so you can see how much a lower rate or shorter term would save before you commit.
Is this a mortgage quote or financial advice?
No. It's an estimate to help you compare scenarios. It doesn't include property taxes, insurance, PMI, or fees, and it isn't a loan offer — use it to plan, then confirm exact numbers with your lender.
How much does the interest rate affect my total cost?
Significantly. On a $200,000 30-year loan, the difference between 5% and 7% is about $270 in monthly payment — but the total interest paid over 30 years differs by roughly $97,000. Even a 0.5-point rate improvement saves tens of thousands of dollars on a large, long-term loan, which is why shopping lenders and improving your credit score before applying can be highly valuable.
What happens if I make extra payments?
Extra principal payments reduce your balance faster, which means less interest accrues each subsequent month, accelerating payoff. On a 30-year mortgage, adding $200/month to principal can cut 5–7 years off the term and save substantial interest. This calculator models a standard payment schedule — it doesn't model extra payments, but comparing a shorter-term loan (e.g., 20 instead of 30 years) shows a similar effect.
Why does a $300,000 mortgage end up costing nearly $720,000?
On a 30-year fixed mortgage at 7%, the standard amortization formula produces a monthly payment of $1,996. Multiply that by 360 payments and the total outlay is $718,560 — more than twice the original loan. That gap is not a bank trick or a hidden fee. It is a mathematical consequence of how compound interest works when a large balance is paid down slowly over a long period. Understanding why this happens — and what you can do about it — is the most practical thing the amortization table shows you.
How the monthly payment is calculated
The fixed monthly payment is determined by the formula P = L × [r(1+r)^n] / [(1+r)^n − 1], where L is the loan principal, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of payments (years × 12). This formula solves for the constant payment that produces a balance of exactly zero at payment n. Every payment is the same dollar amount, but the internal split between interest and principal shifts with each one.
Why early payments are almost entirely interest
Interest accrues each month on the remaining balance. At the start, the full loan amount is outstanding, so the interest charge is at its maximum. On a $300,000 loan at 7%, the first payment's interest component is $300,000 × (0.07 ÷ 12) = $1,750 — leaving only $246 of the $1,996 payment going to principal. The next month, the balance is $299,754, so the interest is slightly less, and slightly more goes to principal. This snowball effect accelerates, but slowly: it takes about 22 years to pay off half the principal on a 30-year mortgage.
What the amortization table actually tells you
The year-by-year schedule shows exactly when the balance crosses meaningful thresholds. It also reveals the outsized value of extra principal payments early in the loan: an extra $200 a month in years one through five reduces the total interest by far more than $200 a month in years twenty-five through thirty, because early extra payments have more remaining interest to prevent. The table is the tool that makes this visible.