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Create detailed schedules
Generate complete amortization schedules with principal, interest, balances, totals, and payoff timing.
Editable amortization schedule software for Windows · $49 one-time
Professional Amortization Software for Windows Build, Edit, Save, and Print Loan Schedules.
Change a payment date, payment amount, interest rate, or extra principal amount and let the remaining schedule recalculate automatically. Save the loan, reopen it later, and print professional reports.
$49 one-time · No subscription · Secure PayPal checkout
How registration works
After purchase, registration is simple and support-assisted.
- 1Pay with PayPalComplete secure checkout.
- 2Open Register SoftwareOpen the program's registration screen.
- 3Send your IDEmail your Installation ID or User ID.
- 4Enter your passcodeWe send your registration passcode.
Include the name or email used for PayPal so we can match your purchase. support@powerofinterest.com
Use the free online schedule calculator · Refund policy · License terms
- ✓Windows 11, 10, 8, 7
- ✓Trusted since 1999
- ✓U.S. phone & email support
Why choose Amortization Pro
Built for real loan work, not just quick estimates.
Use one practical Windows workspace to build complete amortization schedules, adjust changing loan terms, and keep accurate payment records.
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Edit with ease
Change payments, dates, interest rates, and notes on individual rows without rebuilding the whole loan.
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Automatic recalculation
Update the remaining schedule instantly after an extra payment, a changing rate, or another loan change.
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Save, retrieve & print
Store loans for later, reopen them quickly, and print clean schedules, totals, and professional reports.
Since 1999Loan and interest software
One-time purchase optionsNo forced monthly subscription
Free evaluationsTry Windows software before buying
U.S.-based support(608) 444-6575 · support@powerofinterest.com
Choose the right version
Choose the version that fits what you need.
Use the free online calculator for quick schedules, test the Windows program with the free evaluation, or register Amortization Pro to edit, save, reopen, and print your loans.
Free Schedule Calculator
$0 runs in your browser
- Build complete amortization schedules
- Review totals, charts, and annual summaries
- Print the schedule and report
- Individual payment rows remain view-only
Windows Evaluation
$0 five unrestricted uses
- Install and evaluate the desktop software
- Use full loan amounts for five schedule uses
- After five uses, principal is fixed at $60,000
- Register later without reinstalling
Amortization Pro
$49 per license
- Edit payment dates, amounts, rates, and notes
- Recalculate all later rows automatically
- Save and retrieve loan schedules
- Print annual totals and complete reports
- Use any loan principal amount
- Choose 1 license for $49 or 4 licenses for $196
See the software
Loan terms, totals, and charts in one clear workspace.
Enter the loan once
Set the principal, rate, dates, payment frequency, and calculation method, then build the full schedule.
Review the complete picture
See total interest, total paid, payoff date, remaining balance, and annual interest-versus-principal charts.
Specialized loan tools
Focused Windows tools for specific loan jobs.
Need a more specialized loan task? These Windows programs handle payoff calculations, escrow analysis, payment coupons, mortgage payoff planning, and irregular loan histories.
$25 one-time purchase
Daily Interest & Payoff Calculator Pro
Calculate per-diem interest and payoff amounts, save calculations, and create professional one-page payoff worksheets.
$25 one-time purchase
Mortgage Payoff Calculator
See how extra mortgage payments change your payoff month, time saved, and total interest.
$25 one-time purchase
Loan Payment Coupon Book Pro
Create dated payment coupon books for private loans, seller financing, mortgages, and installment loans.
$25 one-time purchase
RESPA Escrow Analysis Pro
Prepare initial or annual escrow disclosures and run a 12-month aggregate escrow analysis.
$50 one-time purchase
Loan Reconciliation & Payoff Pro
Reconstruct irregular payment histories and calculate a payoff through a selected date.
All software shown here is a one-time purchase with no subscription. Pay securely through PayPal. Refund policy · License terms
A real amortization example
See what one extra principal payment changes.
This example uses a $250,000, 30-year loan at 6.50% with a regular monthly principal-and-interest payment of $1,580.17. A $10,000 principal payment is entered after payment 12.
No extra payment
- Monthly payment
- $1,580.17
- Total interest
- $318,861.22
- Scheduled payoff
- 360 months
- Balance after payment 12
- $247,205.69
$10,000 extra after month 12
- Monthly payment
- $1,580.17
- Total interest
- $269,588.24
- Estimated payoff
- 323 months
- Balance after payment 12
- $237,205.69
Difference in this example
$49,272.98less interest37 monthsearlier payoffIllustrative principal-and-interest calculation only. Actual lender posting methods, fees, rounding, dates, and loan terms may change the result.
Private Loan Manager · $99 one-time purchase
Manage the loans you have made — not just the schedule.
Private Loan Manager is Windows software for lenders, seller-financers, and businesses that need to record actual payments and know what each borrower owes today.
- Manage multiple private and seller-financed loans from one portfolio.
- Post payments and track principal, interest, fees, and outstanding balances.
- See current balance, amount past due, payoff, and balance as of a selected date.
- Prepare year-end principal and interest totals for one loan or the full portfolio.
Actual loan portfolio screen
40 free online tools
Answer real money questions—not just loan formulas.
Use 40 free calculators for loans, mortgages, payoff planning, interest, investing, savings, debt, and retirement. Nothing to install, and your entries stay in your browser.
When Will I Reach $1 Million?
Estimate how long your current balance and monthly investments could take to reach $1 million or another wealth target.
Open calculator →Debt Snowball vs. Avalanche
Enter your debts once and compare payoff time, interest, and target order under both popular payoff strategies.
Open calculator →Buy vs. Rent Calculator
Compare home equity with renting and investing the difference, including transaction costs and ongoing ownership expenses.
Open calculator →15-Year vs. 30-Year Mortgage
Compare monthly payments, lifetime interest, mortgage balances, and the invest-the-payment-difference scenario.
Open calculator →What Does This Loan Really Cost?
Combine interest, origination fees, other upfront fees, and recurring fees to see total borrowing cost and an estimated fee-adjusted APR.
Open calculator →Mortgage Payoff Calculator
Model monthly, annual, and one-time extra principal payments to estimate payoff month, time saved, and interest saved.
Open calculator →Retirement Savings Calculator
Project a nest egg, estimate annual portfolio withdrawals, and compare the result with a retirement-income target.
Open calculator →Daily Interest & Per Diem Calculator
Calculate a daily interest rate and per-day dollar amount, then compare Actual/360, Actual/365, and Actual/366 results.
Open calculator →Also available: investment growth · savings goals · credit card payoff · debt snowball · debt avalanche · refinancing · daily interest · APR · seller financing · construction interest · and more.
Financial math & formulas
See the math behind interest and loan calculations.
Understand the calculations behind your results with worked examples for amortization, daily interest, rate conversions, and other loan formulas.
Daily Interest Formula
Calculate interest per day and compare 360-, 365-, and 366-day conventions.
Show the math →Annual Rate to Daily Rate
Learn when to divide by 365 and when to use an effective equivalent-rate formula.
Convert the rate →Loan Amortization Formula
See how a fixed payment is calculated and why principal and interest change over time.
See the formula →Expanded amortization library
Learn the loan math behind the schedule.
Learn how amortization schedules work, compare loan strategies, troubleshoot schedule differences, and understand principal, interest, payoff, and seller financing.
What Is Principal in a Loan?
See how each payment changes the outstanding balance.
Read guide →15-Year vs. 30-Year Amortization
Compare monthly payment, total interest, and balance milestones.
Read guide →Nominal vs. Effective Interest Rate
Understand quoted rates and the effect of compounding.
Read guide →Early Loan Payoff
Separate remaining principal from future interest.
Read guide →Seller Financing Amortization
Model private notes, regular payments, and balloon balances.
Read guide →Common Schedule Errors
Troubleshoot dates, rates, frequency, rounding, and extra payments.
Read guide →Questions
Frequently asked questions
What does Amortization Pro cost?
Amortization Pro is $49 per license. A 4-license pack is $196. Each purchase is a one-time charge with no subscription or recurring fee.
What is different about the free online version?
The free version builds and prints schedules, but individual payment-row dates, payment amounts, rates, and notes are view-only.
What is the downloaded evaluation?
It is the Windows desktop software. It allows five unrestricted schedule uses. After that, the principal is fixed at $60,000 until registration. Compare the free calculator, evaluation, and Amortization Pro schedule software.
How is the software registered?
After purchasing through PayPal, open Register Software and email the Installation ID or User ID shown by the program to support@powerofinterest.com. Include the name or email used for PayPal. We will send the passcode for that installation.
How do I get help?
Need help? Call (608) 444-6575 or email support@powerofinterest.com.
Ready to build an editable loan schedule?
Try Amortization Pro free on Windows, then register for $49 with no subscription.
Need multiple installations? 4-license pack — $196 · Refund policy · License terms