About the Amortization Calculator
Amortization Calculator helps estimate the key numbers involved in mortgage & real estate decisions. It is designed for quick scenario comparison: enter a realistic set of values, calculate the result, then change one assumption at a time to see what has the greatest effect. Unlike a static table, the result responds to your inputs and keeps the calculation in your browser. Amounts are displayed in U.S. dollars for consistency, but the mathematical formulas can be used with another currency when every monetary input uses that same currency.
How to use this calculator
Enter values that match your situation and select Calculate result. Review the main result and its supporting figures, then change one input at a time to compare scenarios. Results are rounded for readability while the calculation retains additional precision internally.
Information you will need
- Loan amount
- Interest rate
- Loan term
How the calculation works
Standard amortization breakdown for a fixed-rate loan. Read the primary result together with the supporting values rather than focusing on one number alone. A useful estimate should make its assumptions visible. If the answer looks surprising, verify the unit, rate, time period, and whether the entered value is gross or net. Run a conservative and an optimistic scenario to understand the range of possible outcomes.
Formula or method
Payment = P × r(1+r)n / ((1+r)n - 1).
Worked example
$250,000 at 6.5% for 30 years costs about $1,580/month.
The example is illustrative rather than a recommendation. Use your own verified values and keep all monetary or measurement units consistent. When comparing alternatives, save or note each result so the assumptions do not become mixed.
How to interpret the result
The primary output answers the main question posed by the amortization calculator, while the additional cards provide context. A result with many decimal places is not necessarily more certain. The displayed precision makes comparison easier, but uncertainty in the inputs can be larger than the rounding difference.
Compare the result with a second scenario using a less favorable rate, return, cost, or time period. This sensitivity check often provides more useful planning information than one best-case projection.
Limitations and important notes
The amortization calculator is a planning tool, not a quote, filing calculation, lending decision, or promise of future performance. It does not automatically retrieve live market rates or apply every fee, tax bracket, program rule, product limit, or state law. Rules for products such as FHA, VA, Social Security, retirement accounts, and taxes can change. Confirm time-sensitive values with the lender, plan administrator, IRS, SSA, or another relevant authority before acting.
Frequently asked questions
What is an amortization schedule?
An amortization schedule shows each monthly payment split between principal and interest over the life of the loan. Early payments are mostly interest; later payments are mostly principal. The schedule also tracks the remaining balance after every payment, so you can see exactly how many months remain and how much total interest you will pay. This calculator generates a full schedule for any loan amount, rate, and term.
How does amortization work?
Each payment covers interest on the remaining balance first, then reduces principal. As principal decreases, less interest accrues each month, so more of your payment goes toward principal over time. This is why early payments feel like they make little progress. With a fixed-rate loan, the total payment stays the same while the principal-to-interest ratio shifts each month for the life of the loan.
What is the difference between amortization and depreciation?
Amortization spreads loan payments over time. Depreciation allocates the cost of a physical asset over its useful life. Both involve spreading costs, but amortization is for loans and intangible assets while depreciation is for tangible assets like buildings and equipment. For real estate investors, depreciation can also produce tax deductions that offset rental income, which is a separate concept from how your mortgage is amortized.
How do extra payments affect my amortization?
Extra payments go directly to principal, reducing the balance faster. This shortens the loan term and reduces total interest, and the amortization schedule updates to show the new payoff date and interest savings. Because interest is calculated on the remaining balance, paying extra early in the loan has the largest impact. For example, adding $100/month to a $250,000 mortgage at 6.5% saves over $40,000 in interest.
Why is most of my early payment going to interest?
Lenders calculate interest on your remaining balance each month. Early on the balance is at its largest, so the interest portion of your payment is highest. As you pay down principal, the interest owed shrinks and more of your fixed payment goes to principal. This is why a 30-year mortgage takes roughly 20 years just to reach the halfway point of principal paid. Extra principal payments accelerate the shift by reducing the balance faster.
How do I calculate the principal paid on a mortgage?
For any given payment, interest equals the current balance multiplied by the monthly rate, and principal is your payment minus that interest. For example, on a $200,000 loan at 6% (0.5% monthly), the first payment of about $1,199 includes roughly $1,000 in interest and only $199 in principal. Subtracting interest from each payment reveals the principal portion. An amortization schedule does this calculation for every payment automatically.
How does loan term length affect total interest?
A longer term spreads payments over more years, lowering your monthly payment but greatly increasing total interest. On $250,000 at 6.5%, a 30-year term costs about $319,000 in total interest, while a 15-year term costs roughly $142,000. That is a savings of about $177,000. The amortization schedule clearly shows how term choice trades lower monthly payments for higher lifetime interest costs.