Amortization Formula and Worked Example
Calculate a payment and follow the first schedule rows.
Read guide →Expanded guide library
Amortization Guides, Examples and Loan Education
Use worked examples and focused explanations to understand principal, interest, payment timing, payoff strategies, rate changes, special loan structures, and schedule accuracy.
24 focused guides
Find the loan question you need to solve.
Each guide covers one specific concept and links to calculators or software when a numerical schedule helps.
Core amortization
What Is Principal in a Loan?
See how the outstanding balance changes with each payment.
Read guide →Why Early Payments Are Mostly Interest
Follow the first payment and the shift from interest to principal.
Read guide →15-Year vs. 30-Year Amortization
Compare payment, total interest, and balance milestones.
Read guide →Common Amortization Schedule Errors
Audit rates, dates, frequencies, rounding, and extra payments.
Read guide →Simple Interest vs. Amortized Interest
Compare a fixed principal simple-interest example with a declining-balance loan.
Read guide →Interest rates and timing
Amortization vs. Compound Interest
Separate repayment mechanics from interest-on-interest growth.
Read guide →Nominal vs. Effective Interest Rate
Convert a quoted nominal rate to an effective annual rate.
Read guide →Effective Interest Rate vs. Discount Rate
Understand two rates that use different bases.
Read guide →Daily Interest vs. Monthly Interest
See how day counts and actual dates change interest.
Read guide →Changing Interest Rates
See a loan change from one rate to another.
Read guide →Fixed vs. Variable-Rate Amortization
Understand reset dates, indexes, caps, and recalculation.
Read guide →Inflation and Fixed Loan Payments
Separate contractual dollars from purchasing-power effects.
Read guide →Payoff and strategy
Extra-Payment Amortization Schedule
See how one principal payment changes interest and payoff.
Read guide →Early Loan Payoff
Compare remaining principal with future interest.
Read guide →Personal Loan Amortization
Review payment, balance, and extra-principal strategies.
Read guide →Biweekly Loan Amortization
Compare monthly and accelerated biweekly structures.
Read guide →Refinancing an Amortization Schedule
Compare the old remaining loan with proposed new terms.
Read guide →Special loan structures
Balloon-Payment Amortization
Calculate the balance due at an early maturity date.
Read guide →Interest-Only and Negative Amortization
Learn when payments hold principal steady or let it grow.
Read guide →Seller Financing Amortization
Track private notes, payments, and balloon balances.
Read guide →Escrow and Loan Payments
Separate taxes and insurance from principal-and-interest amortization.
Read guide →Equity and education
Home Equity and Amortization
See how principal reduction changes the debt side of equity.
Read guide →Teaching Amortization
Use a practical one-hour financial-literacy lesson plan.
Read guide →Software reference
Windows Amortization Software
Compare the free online schedule, five-use Windows evaluation, and registered $25 desktop version.
Compare software versions →Build a schedule while you learn.
Use the free online calculator or download the Windows evaluation.
Put the guide concepts into numbers.
Use twelve free calculators for payments, extra principal, payoff, daily interest, balloon balances, biweekly schedules, Rule of 78, and refinancing.