Calculator guide
Amortization Calculator helps you explore the stated finance question. Start with the labelled inputs, then review the method, worked example and limitations before using a result.
Formula or method
Payment = P×r÷(1−(1+r)^−n). Each month, interest = opening balance×r, principal repaid = payment−interest, and closing balance = opening balance−principal repaid. Extra payments reduce principal; the last payment is capped at the remaining amount due.
How to use this calculator
- Enter principal, annual interest rate and loan term.
- Inspect the principal and interest breakdown; taxes and fees are separate.
Worked example
A loan of 1,200 at 0% APR over 1 year with no extra payment has 12 payments of 100 and no interest. An extra 20 monthly repays it in 10 payments of 120.
Understanding the result
Compare the output with the amortization calculator worked example using exactly the same inputs. A different assumption or rounding convention can produce a different displayed result; the output does not establish personal or professional suitability.
Limitations and assumptions
- Fixed monthly rates and immediate application of extra principal are assumed. Fees, escrow, irregular dates, prepayment penalties, and lender rounding can change an actual schedule.
- The worked example demonstrates the stated assumptions, not a recommendation about your personal circumstances.
Frequently asked questions
Which inputs should I check first?
Follow the Amortization Calculator input instructions above. Check each measurement, date, selection or expression before comparing results.
Why might my result differ from another tool?
Compare the other tool's amortization calculator method, input units, rounding and assumptions. A matching title does not guarantee that both tools answer the same question.
Does a linked reference certify this result?
No. A reference can explain a formula or provide background for Amortization Calculator, but it does not endorse this website, validate personal inputs or establish professional suitability.
Sources
Educational and planning information only. Sources are attributed background or formula references, not endorsements. Verify consequential decisions with an appropriate qualified professional.