Finance Calculators
Amortization Calculator
Amortization Calculator build a loan amortization schedule and measure the effect of optional extra monthly payments.
Finance Calculators
Amortization Calculator
Build a loan amortization schedule and measure the effect of optional extra monthly payments.
Formula
Monthly payment P = Lr(1+r)^n / ((1+r)^n - 1), with r equal to the monthly rate. Each schedule row applies interest to the opening balance, then principal and any extra payment, without allowing the balance to fall below zero.
About the Amortization Calculator
Build a loan amortization schedule and measure the effect of optional extra monthly payments. Finance calculators apply the displayed cash-flow, growth, repayment, return, or valuation equation to the entered monetary assumptions.
How the Amortization Calculator Works
Monthly payment P = Lr(1+r)^n / ((1+r)^n - 1), with r equal to the monthly rate. Each schedule row applies interest to the opening balance, then principal and any extra payment, without allowing the balance to fall below zero.
The calculation runs in your browser. Submitted values are validated for the required numeric range, data shape, units, and method-specific restrictions before a result is shown.
Required Inputs
- Loan principal (required)
- Annual interest rate (%) (required)
- Loan term (years) (required)
- Extra monthly payment (optional)
Results Reported
The result panel shows the final answer together with the intermediate quantities needed to audit the calculation. Depending on this method, reported values include:
scheduled_paymentactual_monthly_paymentpayoff_monthsmonths_savedtotal_interestinterest_savedtotal_paidamortization_schedule
Amortization Calculator Example
Use the example data button, calculate, then review the result table, formula, and worked solution before using the answer.
| Input | Example value |
|---|---|
| Loan principal | 250000 |
| Annual interest rate (%) | 6.5 |
| Loan term (years) | 30 |
| Extra monthly payment | 200 |
How to Use the Calculator
- Confirm that the calculator title and method match the quantity, test, conversion, or planning question you need to solve.
- Enter values with compatible units and the requested sample, group, matrix, count, date, or option format.
- Select Example Data to inspect a valid input layout, or enter your own values and select Calculate.
- Review the result table, formula, worked substitutions, warnings, and interpretation rather than using only the headline number.
- Use Copy Result or Download CSV when you need a reusable record of the displayed calculation.
Understanding the Result
Rates, timing conventions, fees, taxes, inflation, and rounding can materially change real-world results; review the displayed assumptions before acting.
Keep the entered values, units, selected options, and any warning shown beside the result. For a hypothesis test, report the statistic, degrees of freedom where applicable, p-value, alpha level, effect size, and decision. For an estimate or conversion, report the formula convention and final unit.
Accuracy and Limitations
The calculator keeps full browser precision during calculation and rounds only for display. Accuracy still depends on correct inputs and on whether the displayed model represents the real problem. Educational calculators cannot replace required professional review, current official rules, field measurements, laboratory methods, or specialist statistical software where those are necessary.
Frequently Asked Questions
What does the Amortization Calculator calculate?
Build a loan amortization schedule and measure the effect of optional extra monthly payments.
Which formula does the Amortization Calculator use?
Monthly payment P = Lr(1+r)^n / ((1+r)^n - 1), with r equal to the monthly rate. Each schedule row applies interest to the opening balance, then principal and any extra payment, without allowing the balance to fall below zero.
Is this a separate calculator?
Yes. This page has its own public URL, inputs, formula notes, browser function, fixture, and worked solution.
What should I verify before using the answer?
Check the entered values, units, selected options, formula convention, warnings, and result interpretation shown on this calculator page.